Description of the device amd radeon hd 7800 series. AMD Radeon Graphics Card Families Reference. Tessellation and geometry processing

Chip codename: "Tahiti"
4.3 billion transistors (more than 60% more than the Cayman, and exactly double that of the Cypress)
384-bit memory bus: six 64-bit controllers with support for GDDR5 memory
Core frequency: up to 925 MHz (for Radeon HD 7970)
32 GCN computational units, including 128 SIMD cores, consisting of a total of 2048 ALUs for floating point calculations (integer and floating point formats, FP32 and FP64 precision support within the IEEE 754 standard)
128 texture units, with support for trilinear and anisotropic filtering for all texture formats
32 ROPs with support for anti-aliasing modes with the possibility of programmable sampling of more than 16 samples per pixel, including FP16 or FP32 framebuffer format. Peak performance up to 32 samples per cycle, and in Z only mode - 128 samples per cycle
Integrated support for six monitors including HDMI 1.4a and DisplayPort 1.2

Radeon HD 7970 Graphics Card Specifications

Core frequency: 925 MHz
Number of universal processors: 2048
Number of texture units: 128, blending units: 32
Effective memory frequency: 5500 MHz (4 × 1375 MHz)
Memory type: GDDR5
Memory capacity: 3 gigabytes
Memory bandwidth: 264 gigabytes per second
Theoretical maximum speed shading: 29.6 gigapixels per second
Theoretical texture sampling rate: 118.4 gigatexels per second.
Two CrossFire connectors
PCI Express 3.0 bus
Power consumption: 3 to 250 W
One 8-pin and one 6-pin power connector
Two-slot design
MSRP: $ 549

Radeon HD 7950 Graphics Card Specifications

Core frequency: 800 MHz
Number of universal processors: 1792
Number of texture units: 112, blending units: 32
Effective memory frequency: 5000 MHz (4 × 1250 MHz)
Memory type: GDDR5
Memory capacity: 3 gigabytes
Memory bandwidth: 240 gigabytes per second.
Maximum theoretical fill rate: 25.6 gigapixels per second
Theoretical texture sampling rate: 89.6 gigatexels per second.
Two CrossFire connectors
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, two Mini-DisplayPort 1.2
Power consumption: 3 to 200 W
Two-slot design
MSRP: $ 449

Noteworthy is the high complexity of the new chip - 4.3 billion transistors, which is more than half the number of transistors in the previous top-end GPU. The opportunity to make such a complex crystal was provided by the use of a modern 28-nanometer process technology, and the new chip in terms of area turned out to be even slightly smaller than the Cayman size. And its practical characteristics that affect performance have been noticeably improved: the number of ALUs, TMUs, the memory bus. Only the number of ROPs did not increase, and the frequency of the GDDR5 video memory remained at the same mark.

The principle of naming the company's video cards has remained the same. Radeon HD 7970 is the most productive single-chip solution of the company, after a while the younger model HD 7950 was released, announced a little later. Initially, the HD 7970 had no competitors in the market and did not replace any specific video card from the AMD line, but rather pushed it down. As for the comparison with the competitor, NVIDIA released its 28-nanometer solution much later.

The same GDDR5 memory is installed on the new AMD video card, but its volume, instead of 2 gigabytes in the previous generation, has grown to 3 gigabytes. This happened due to the expansion of the memory bus from 256-bit to 384-bit. And now you can put either 1.5 GB or 3 GB on the new board. Naturally, from a marketing point of view, installing a smaller volume would be a clear disadvantage, so the decision was made to install 3 GB, although today this is a bit overkill. Only in ultra-high resolutions and with MSAA 16x 1.5-2 GB is not enough. However, AMD also has Eyefinity, and for games on three or more monitors, the screen buffer will just take up a very large amount.

So, let's take a look at the Radeon HD 7970. The new video card of the upper price range has a two-slot cooling system, which is covered with a plastic casing, which is usual for all modern AMD motherboards, along the entire length of the card. Only the design of this casing has changed slightly, although rear part still extends beyond the PCB. But the design of the strip with leads was changed - to improve the cooling of the video card, one of the two slots (half of the strip) was occupied exclusively by the ventilation hole for heat dissipation.

But users shouldn't be hurt by the reduction in the number of DVI connectors wired directly to the board. For their convenience, a special HDMI-DVI adapter will be included in the package, which will allow you to connect two monitors with DVI connectors. By the way, the power consumption of the new card is not lower than that of the Radeon HD 6970, so a set of one 8-pin and one 6-pin power connectors had to be installed on it.

But in the new Radeon HD 7970 the cooling system has changed for the better. A new generation of the evaporation chamber and a new cooler with a larger size, with a changed shape of the blades and increased performance (more air flow is provided) are used. As a result, there is an increase in the efficiency of the cooler with a simultaneous decrease in noise.

The switch has not gone anywhere from the board. Dual firmware BIOS, which we wrote about in the description of the Radeon HD 6900. In short: the video card has two BIOS versions, one with the possibility of custom flashing, and the other with hardwired firmware at the factory. This convenient solution attracted both users and AMD itself so much that it decided to continue to equip them with top-end solutions.

One can only greet this decision, which really helps in various cases related to both unexpected problems during flashing (power off during the process, for example), and allows you to fearlessly conduct various experiments with BIOS images. Not surprisingly, AMD has hinted at the excellent overclocking capabilities of the new graphics card over and over again:

As you can see, overclocking to a frequency of 1 GHz and higher is practically promised, if you do not take into account the small inscription (which was not included in the screenshot) that the warranty ceases to apply even if the video card is out of order as a result of an experiment with raising the frequency from the settings video driver.

Architectural features of the Radeon HD 7970

To assess the relevance of architectural modifications in the Southern Islands, let's first look at the evolution of the GPU over the past few years as seen by AMD. Until 2002, graphics chips were a specific Hardware, capable exclusively of graphical calculations. Video chips of that time had limited functionality, they only knew how to apply and filter textures, process geometry, engage in primitive rasterization, and therefore were not at all suitable for general-purpose computational tasks.

Over the next few years, basic programmability was added to the GPU, but also focused exclusively on graphics tasks. That was the time of support for DirectX 8 and 9, limited in functionality of shader programs with the ability to calculate with floating point. Video chips of that time had specialized ALUs for vertex and pixel processing, as well as dedicated caches for pixels, textures and other data. Versatility was still not even close.

It was only in 2007 that AMD acquired a unified DirectX 10 shader architecture, as well as GPU programming capabilities using special tools: CAL, Brook, ATI Stream. GPUs of that time already had advanced caching and support for local and global shared data. Architecturally, the chips were based on the VLIW5 and VLIW4 blocks, flexible enough for some basic non-graphical computations, but still focused on graphics algorithms.

Now is the time for a new architecture that is even better suited for general-purpose computing - Graphics Core Next (GCN)... For AMD, this is a new architectural era, which is why the name was chosen this way. The new GPUs offer excellent graphics processing capabilities and performance, but the architectural changes made are intended primarily to improve the position in non-graphics computing - increasing performance and efficiency in complex general-purpose tasks. The new GPU design is designed for so-called heterogeneous computing - a mixture of graphics and general-purpose in a multitasking environment. GCN architecture has become more flexible and should be even better suited for energy efficient execution of various tasks.

The basic block in the new architecture is the GCN block. These are the building blocks of all the new Southern Islands GPUs. The architecture for the first time for AMD graphics chips uses a non-VLIW design, it uses vector and scalar blocks, and one of the most important changes is that each of the GCN computational blocks has its own scheduler and can execute instructions from various programs (kernel).

The new computing architecture is designed for high efficiency in loading computing units in a multitasking environment. The computational block GCN is divided into four subsections, each of which works on its own stream of instructions every clock cycle. Streams can also use the scalar block available in GCN for flow control or pointer operations. The combination of vector and scalar blocks offers a very simple programming model. For example, pointers to functions and the stack (function pointers and stack pointers) are much easier to program, and the compiler's task is now much simplified, since the execution units are scalar.

Each GCN block has dedicated 64KB local storage for data exchange or local stack expansion for registers. The block also includes a first-level cache memory with the ability to read and write, and a full-fledged texture pipeline (sampling and filtering units). Therefore, the new computing unit is able to work independently, without a central scheduler, which in previous architectures was responsible for the distribution of work by blocks. Now each of the GCN blocks is capable of scheduling and distributing commands by itself, one computing unit can execute up to 32 different flows of commands, which can be from different virtual address spaces in memory and are fully protected and independent from each other.

Previous GPU architectures from AMD used the VLIW4 and VLIW5 architecture models, and although they are good enough for graphics tasks, they are not efficient enough for general-purpose computing, since it is very difficult to load all execution units to work in such conditions. The new GCN architecture offers an equally large number of execution units, but with scalar execution, which removes the limitations and dependencies of registers and instructions. The transition from the VLIW architecture to scalar execution gives a noticeable simplification of code optimization tasks.

When executing instructions on the previous VLIW4 architecture, the compiler has to deal with register conflicts, perform complex allocation of instructions to execution units at the compilation stage, etc. At the same time, nontrivial optimization is often required to achieve high performance, which is suitable for most graphic tasks and much less flexible for other calculations. The new architecture offers significant simplification of development and maintenance, simplified creation, analysis and catching of errors in low-level code, stable and predictable performance.

Memory caching subsystem

Bandwidth and the amount of memory and caches are never enough, and there is always a need and methods to increase them. AMD's new GPUs use a full, dual-level read / write cache. Each computational unit has 16 kilobytes of the first level cache, and the total size of the second level cache is 768 kilobytes (in total, the chip has 512 KB L1 and 768 KB L2), which is 50% more than in the previous chip, which does not have the ability to write at all to L2 cache.

With regard to performance, each GCN computational unit in one clock cycle can receive or write 64 bytes of data from / to the L1 cache or global memory, which is used to exchange data between instruction streams. The same amount of data is capable of transmitting and receiving each section of the L2 cache memory. As a result, the company's top GPU gets 2 terabytes / s for L1 and 700 GB / s for L2, which is 50% more than the previous top AMD solution.

Graphic processor "Tahiti"

Now that we've covered the low-level architectural changes in the new Southern Islands series, it's time to move on to the details of the most powerful solution in this line - the Radeon HD 7900, which includes two models. First of all, let's just note the enormous complexity of the new GPU, because it includes more than 4.3 billion transistors, which is twice as much as in the chip on which the Radeon HD 5870 is based! Naturally, such a powerful chip became possible only thanks to the use of the new 28 nm technical process. So what does it have inside?

The number of geometric blocks has not changed compared to the Cayman, there are still two of them, but their efficiency has been significantly increased - we will dwell on this in more detail a little later. On the graphics processor diagram, we see 32 computing units of the GCN architecture available on the Radeon HD 7970, and in the case of the junior solution, some of them will be disabled. If we consider the peak computing performance of the solution, then it is almost 3.8 teraflops (the number of floating point operations per second), which is an absolute record for a GPU today.

Each GCN block contains 16 texture units, which gives a total figure of 128 TMU per chip, or more than 118 gigatexels / sec - and this is another record at the time of release, and it is far from the last. But the number of ROP blocks has not changed, there are still 32 of them in 8 enlarged RBE blocks. Another interesting architectural change is that now ROPs are "attached" not to memory channels, as it was before, but to GCN blocks.

Although theoretically the write speed to the framebuffer has hardly changed, and the maximum possible are the same 32 color values and 128 depth values per cycle, the practical fill rate (fill rate) in real applications has increased significantly due to the increased memory bandwidth. AMD measured the Cayman to record only 23 pixels per clock, while the new Tahiti came close to its theoretical 32 pixels per clock.

This is understandable, because the new video chip from AMD has a 384-bit memory bus - six 64-bit channels, just like the current top-end solution of a competitor. It is this 1.5-fold increase in memory bandwidth that makes it possible to increase the real speed of texture sampling and writing to the framebuffer. A bandwidth of 264 GB / s should help squeeze close to theoretical values of 118 gigatexels / s and 30 gigapixels / s, and in the practical part we will check this.

In the case of the stripped-down Radeon HD 7950 GPU, Tahiti includes 28 active computing units of the GCN architecture out of 32 physically available on the chip. In the case of the junior solution of the Radeon HD 7970 series, it was decided to disable four of them. Since each GCN unit contains 16 texture units, the total number of TMUs for the new model is 112 TMUs, which gives a performance of almost 90 gigatexels / sec.

But the number of ROPs and memory controllers in the HD 7950 has not changed, they decided not to cut them down and leave the same 32 and 6 pieces, respectively. Therefore, the Tahiti Pro video chip has the same 384-bit memory bus, assembled from six 64-bit channels, as the top solution from AMD. Apparently, it is the computing functional devices that suffer most from defects in production, and they decided not to cut everything else.

Tessellation and geometry processing

From an architectural point of view, nothing special about the Tahiti geometric blocks has changed since the Cayman days. Two blocks are still used for processing (setting vertices and tessellation) of geometric data and rasterization, and the scheme is very similar to the one we saw earlier, except that the tessellators are already called the 9th generation:

Despite the schematic similarities, the latest generation of these blocks is capable of significantly better tessellation and geometry processing performance, as the blocks have undergone significant modifications. Although peak performance has only grown to nearly two billion vertices and primitives per second (925 MHz and two vertices per clock), real performance has grown more. This was achieved by increasing the size of the caches, improving the buffering of geometry data and reuse vertex data.

As a result, tessellation performance is improved at all triangle tiling ratios by up to four times over the previous generation Radeon HD 6970. But four times are not achieved in all cases, even on the diagram from AMD itself:

The diagram shows a comparison of the tessellation performance of the Radeon HD 7970 versus the HD 6970 at split ratios from 1 to 32. And, as you can see, the difference in performance is from 1.7 to 4 times. But this is naked synthetics. And to get closer to reality, let's give more data on the tessellation speed already in gaming applications:

As you can see, AMD's synthetic numbers are well supported by the gaming ones - the performance in real applications with "heavy" tessellation has increased significantly. This is a very good result, which we will definitely check in the practical part, using the example of synthetics and gaming applications.

Non-graphical computing

From the point of view of heterogeneous and non-graphical computational tasks, the emerging two Asynchronous Compute Engines (ACE) are very important. They are designed to schedule and distribute work between execution units for efficient multitasking and work in conjunction with a graphics command processor (Command Processor).

The Radeon HD 7900 has two independent computing engines and one graphics engine. This adds up to three programmable blocks and three instruction streams, completely separate from each other. And in addition to asynchronous command submission for fast context switching, the new GPU also features two bidirectional direct memory access (DMA) controllers introduced with the Cayman. These two controllers are required to take full advantage of the new PCI Express 3.0 bus.

As we know, from the point of view of serious computations, not only the speed of performing single-precision floating-point operations is important, but also double-precision floating point operations. And the new architecture from AMD copes with this task quite well. At the moment, it is assumed that there are two versions of the GCN computational units with different rates of execution of FP64 instructions. For the older GPU, the execution rate is 1/4 of the FP32 speed, and for the lower-end GPUs, the rate is 1/16, which is quite enough to maintain compatibility, but does not complicate inexpensive solutions too much. As a result, the Radeon HD 7970 is capable of 947 billion double precision operations per second (oh, they just barely reached the teraflop!) - this is another highest achievement of the new AMD chip.

Moreover, these are not the same gigaflops as in the case of previous architectures, but more "fat" ones. After all, the efficiency of the new GPU in complex computing tasks must grow seriously. First, the memory and caching subsystem has been improved. Secondly, each GCN computational unit has its own scheduler, which should improve the execution of the branching code and overall efficiency. And thirdly, we note the scalar execution, which does not require complex optimizations from the compiler, as a result of which the computational units will be idle much less often. As a result, it will be easier for the new chip to demonstrate high performance and ALU load in any tasks.

Other computational innovations include full ECC support for DRAM and SRAM. From the software side, it is important that Tahiti is the first GPU with full support for new API versions: OpenCL 1.2, DirectCompute 11.1 and C ++ AMP and their capabilities. For example, OpenCL 1.2 allows you to combine the capabilities of several computing devices into one, and AMD has already released support in the form of AMD APP SDK 2.6 and Catalyst 11.12 driver.

Architecture performance and efficiency

After reviewing all the architectural innovations using the example of the top chip in the Southern Island series, it is time to talk about the effectiveness of all these changes. It is clear that the performance of the new chips is much higher than that of the previous ones; the opposite would be quite surprising. The question is how much faster. In various tasks, figures are obtained from 40-50% (minimum!) To a fivefold difference. Improvements in architecture allow to exceed the theoretical 1.4x dumb gigaflops difference. Let's take a look at this with examples:

The diagram compares the new top-end solution and the previous one-chip: Radeon HD 7970 and HD 6970, which is quite fair. Various performance tests were selected: SmallptGPU and LuxMark are ray tracing on OpenCL, SHA256 is a secure hashing algorithm, and AES256 is a symmetric encryption algorithm. Well, Mandelbrot is a well-known double-precision problem.

The vertical dashed line on the graph marks the theoretical performance difference, but the speed data shows that the new GPU was significantly faster in three out of five tasks. This is due to all the changes aimed at increasing efficiency: moving away from VLIW, the presence of a scheduler in each computational unit, improved caching, etc.

Render quality changes

Actually, this part could well have been skipped, since the image quality in recent times there are no special complaints and cannot be - for various reasons. For example, the quality of full-screen anti-aliasing for video cards from different manufacturers is very similar, especially considering the widespread use of software anti-aliasing methods using post-processing filters performed on all GPUs is absolutely the same.

The same applies to texture filtering - now its quality is such that it is very difficult to distinguish between AMD and NVIDIA solutions, even if we make a pixel-by-pixel comparison. In Radeon HD 6900 - the previous generation of the company - anisotropic filtering has improved a little more, and now even a "microscope" will not help to find any significant drawbacks there. The only remark is that the Radeon video cards were slightly inferior to the GeForce in motion due to more noticeable specific artifacts, such as "noise" or "sand".

With the release of new-generation video chips, the texel weights in the texture filter were revised once again, modifying them so as to reduce such artifacts sometimes seen on the Radeon HD 6900 in the presence of certain types of textures (high-frequency ones, with sharp transitions from dark to light, for example). Changes in quality are so difficult to show with examples that AMD does not give comparative pictures of HD 7900 versus HD 6900, but simply compares the quality of the "hardware" algorithm with a purely software one, executed on GPU stream processors, and therefore is ideal:

In such a small screenshot, the difference in quality is not visible, but AMD assures that all the changes made did not introduce any performance drop and did not worsen the picture quality in any of the aspects - it still does not depend on the angle and the filtering quality is close to ideal. In one of the future practical materials, we will definitely check this.

Partially Resident Textures

The idea behind Partially Resident Textures (PRT) is to use the hardware capabilities of the presented GPU - virtual memory. Surely many users have already seen id Software's RAGE game, which uses a virtual texturing technology called "MegaTexture", which allows huge amounts of texture data to be used and streamed to video memory.

Using virtual video memory, it is very easy to get effective hardware support for such algorithms, which allows you to use up to 32 terabytes of textures in an application, which makes it possible to create unique locations in games, without repeating pieces of textures, with no problems with loading texture data. True, AMD gives an illustrative example that is too strange, from which nothing is particularly clear:

PRT helps you achieve high picture quality and helps to improve the efficiency of video memory. Algorithms like these are already in use in id Software's engine and are expected to appear in many next-generation engines. The games of the future need to work with huge amounts of data and the advantage of the new GPU is that the local graphics memory in algorithms a la PRT works like a hardware cache memory, and textures are loaded into it if necessary. GPUs of the Southern Islands family support "megatextures" up to 32 terabytes (up to 16384 × 16384 resolution) and, most importantly, hardware texture filtering for them, which is not available on earlier video chips.

Virtual textures are split into 64 kilobyte chunks (kilobytes, not texels) and this chunk size is fixed. And only those of them that are needed when rendering the current frame are loaded into the local memory of the video card. The technology works regardless of the texture format, just the sizes of chunks in texels will differ. For example, for a regular uncompressed texture with 32 bits per color, the chunk size will be 128 × 128 texels, and for compressed in DXT3 format - 256 × 256 texels.

The technology also involves the use of mip-levels of textures (reduced copies used for texture filtering). They require multiple access when rendering and filtering. Let us consider the operation of the algorithm using an example.

In this figure, four different chunks from different mip levels are highlighted for rendering. When a shader program requests data from them, some of the chunks are already in local memory and this data is immediately sent to the shader for further calculations. But some chunks are missing from the table, and the application must choose to follow up on such a miss. For example, you can request data from a lower resolution mip-level, then the image will be fuzzy, but at least it will look like the truth and will be rendered without delay. And by the time the next frame is rendered, it can already be loaded into the cache - local video memory. RAGE players will understand us.

This is a powerful algorithm that allows you to use huge textures that are unique for each of the objects. Similar algorithms have long been used in offline rendering, except for the need for real-time calculations. AMD even made a demo program using the Per-Face Texture Mapping technique developed by Walt Disney Animation Studios for their animated films. Unfortunately, the demo is not ready yet, and we only saw low resolution screenshots.

The essence of this texture mapping technique is to assign a certain piece of texture to each polygon, without the need to use a UV transformation (finding a correspondence between the coordinates of the surface of a three-dimensional object and coordinates on a two-dimensional texture). This approach solves some of the problems with creating tessellated content by making the displacement mapping algorithm very simple. And PRT in this method is used for efficient storage and access to texture data.

Media handling instructions

An interesting innovation in Southern Islands seems to be support for specialized instructions used in image processing, both static and dynamic. For example, a widely used instruction called Sum of Absolute Differences, better known as SAD (Sum of Absolute Differences), has been improved. The speed of its execution is a very performance-critical bottleneck of many algorithms for image and video data processing, such as motion detection, gesture recognition, image search, computer vision, and many others.

But in the review of the ancient video card Radeon HD 5870, we already wrote about SAD support. Now, in addition to the usual SAD (4 × 1) in Southern Islands, there is a new instruction - QSAD (Quad SAD), which combines SAD with shift operators to increase performance and energy efficiency, as well as a "masking" instruction MQSAD, which ignores the background pixels and is used to isolate moving objects in the frame from the background.

The new GPUs can process up to 256 pixels per GCN compute unit per clock, which in the case of the model AMD Radeon The HD 7970 stands for the ability to process up to 7.6 trillion pixels per second in the case of 8-bit integer color values. While this is a theoretical figure, the visual processing capabilities of the new GPUs are impressive — many video processing tasks can be performed in real time.

PCI Express 3.0

We could not pass by the support of the third version of PCI Express by the entire line of new graphics solutions from Southern Islands. This support was quite expected, since the specifications of the third version of PCI Express were finally approved back in the fall of 2010, but there were still no hardware solutions with its support, although motherboards are already appearing, video cards were released at the end of 2011, and central processing units there are corresponding ones.

The updated interface has a transfer rate of 8 gigatransactions per second instead of 5 GT / s for version 2.0, and its throughput has doubled again (up to 32 Gb / s), compared to the PCI Express 2.0 standard. The new bus uses a different encoding scheme for data sent over the bus, but compatibility with previous PCI Express versions has been retained.

The first motherboards with PCI Express 3.0 support were presented in the summer of 2011, mainly based on the Intel Z68 chipset, and they appeared on the market only in the fall of the same year. So the video cards arrived in time, and AMD in terms of the speed of release of new graphics processors with support for the most advanced technologies again became ahead of the rest. But it is too early to judge whether PCI-E 3.0 will be of any practical use.

AMD PowerTune Technology

One of the most exciting innovations in the Cayman was PowerTune's advanced power management technology. Flexible GPU power management has been used for a long time, but before the Radeon HD 6900, all these technologies were quite primitive and mostly software methods and changed the frequency and voltage stepwise, not being able to turn off large parts of video chips.

Even in the Radeon HD 5000 family, a performance limiter appeared when a certain level of consumption was exceeded, and in the Radeon HD 6900 the system moved to a qualitatively new level. For this, special sensors were included in the chip in all blocks that track the loading parameters. The graphics processor constantly measures the load and power consumption and does not allow the latter to go beyond a certain threshold, automatically adjusting the frequency and voltage so that the parameters remain within the specified thermal package.

Unlike early power management technologies, PowerTune provides direct control over GPU power consumption, as opposed to indirect control by varying frequencies and voltages. This technology helps to establish high frequencies GPU, getting high performance in games, and not being afraid that consumption may go beyond safe limits. After all, most games and common applications that use GPU computing have significantly lower power requirements and do not meet dangerous power consumption limits, unlike stability tests such as Furmark and OCCT.

Even the heaviest games do not require maximum power consumption, and if you limit the frequency consumption by testing video cards with extreme tests, then in the case of 3D games there will be quite a lot of unused performance and power options. In the case when the video card has not reached the safe consumption level, the GPU will work at the frequency set at the factory, and in FurMark and OCCT tests, the GPU frequency will decrease to stay within the consumption limits.

In this way, PowerTune helps to set higher factory frequencies and tune the system to make the most of the GPU resources at the maximum power consumption. In the example shown above, the HD 5870 does not use PowerTune and, due to the GPU frequency limitation by high consumption in endurance tests, does not use all its capabilities. While the maximum TDP is set for the Radeon HD 7970, and the video chip drops frequencies only when it is exceeded, getting the highest possible performance in any applications.

This is clearly shown in the following diagram. In the case of gaming applications, it is possible to achieve TDP by increasing the GPU frequency, and for peak loads by endurance tests, the frequency is reduced to a safe level of power consumption. Without PowerTune, you would have to choose - either to get the probability of a graphics card failure during prolonged FurMark and OCCT operation, or to cut down on the potential performance in games. New technology solves these issues as efficiently as possible.

AMD PowerTune is fast responsive to changing conditions (microseconds) as it is a hardware technology. It is also distinguished by flexible frequency setting, and not stepwise, as it was in the previous chips. All measurements are independent of the driver, but can be adjusted by the user using the settings of the video card.

The difference between PowerTune and the previously accepted approach is that in other cases thermal throttling protection is used, which puts the GPU in a mode of significantly reduced consumption, and PowerTune simply gradually reduces its frequency, bringing the GPU consumption to the set limit. This achieves higher clock speeds and higher performance.

AMD ZeroCore Technology

AMD has not limited itself to the use of power management technology already known from previous solutions. In the first chips in the Southern Islands family, it introduces AMD ZeroCore technology, which helps to achieve even greater energy efficiency in the "deep idle" (or "sleep") mode with the display device disabled, which is supported by all operating systems.

After all, almost any system, even a gaming system, spends most of its time in a low load mode on the graphics processor. And the video card should not consume a lot of power in this mode. And even more so, not to mention the mode with the monitor disabled - in this case, it is advisable to disable the GPU altogether. So AMD did it. Thanks to ZeroCore, in deep idle state, the new GPU consumes less than 5% of the power of full mode, disabling most of the functional blocks in this mode.

AMD gives a schematic comparison with its own Radeon HD 5870, which did not have support for this technology. ZeroCore is an exclusive Southern Islands innovation that comes to desktop solutions from mobile GPUs designed for notebook computers. By the way, the benefits of this technology are associated not only with reduced consumption. In addition, in the long idle mode, when the display is turned off, the video card also completely turns off the fan on the cooler of the video card!

This is exactly what many users have been waiting for. The most interesting thing is that according to our data, laboratory tests of similar PowerTune and ZeroCore solutions took place several generations of video cards ago. Some of the engineering samples of AMD series video cards that left the market for a long time worked exactly like this, completely turning off the cooler when idle.

But it's not just single-GPU users who will benefit from the reduced noise and power consumption of AMD's new ZeroCore-enabled graphics cards. The happy owners of CrossFire systems based on two, three or even four GPUs expect similar improvements. It is logical, after all, that in the rendering mode of the two-dimensional interface of the operating system, all video cards, except for the main one, should not work at all? But this is how they work now!

In the case of CrossFire systems based on video cards with ZeroCore support in 2D mode, all secondary video cards are immersed in deep sleep with minimal power consumption and a disabled cooler. This mode works both for several single-chip video cards and for dual-chip solutions. In addition, the primary CrossFire graphics card will also go into this mode in the event of extended idle times configured in Windows. Clearly, the difference in work looks like this:

By the way, the technology is not as simple as it might seem. AMD engineers had to solve a lot of issues related to the operation of the operating system in idle mode. For example, they found out that Windows tries to update the information on the screen even when the monitor is off. Which, of course, does not allow you to disable the GPU at all. Therefore, the company's programmers had to go a roundabout way, ignoring all the commands for drawing the screen when the monitor is off in sleep mode.

AMD Eyefinity 2.0 Technology

Naturally, the new architecture also found room for improvements to the proven technology for displaying images on multiple monitors - AMD Eyefinity, now in version 2.0. It has new features, higher resolutions, support for more displays and increased flexibility.

This technology is quite interesting, although a very small number of users will find a place in the room and have the courage in front of a family to install more than two monitors. But it is better to be able to always be able to use it than not to have it at all. Moreover, the prices for monitors with large diagonals are almost not going down, but mid-range solutions are constantly getting cheaper.

Indeed, it is now more profitable to buy three 24 "monitors than one 30". AMD gives just such an example, when a 30 "monitor with a 2560 × 1600 resolution costs more than $ 1000, and three 24" FullHD ones can be bought for half that price:

But how to spend your money and space in the room is a personal matter for each user. The main thing is that there is such an opportunity. Plus, Eyefinity 2.0 now supports video output in HD3D stereo mode - something that was lacking in previous solutions, which were inferior in this parameter to competitors. Combining AMD Eyefinity and HD3D technologies, the Radeon HD 7970 graphics card is the first single-chip solution to support three monitors working in stereo mode.

High resolution stereo rendering requires a very fast data transfer interface. And with previous versions of HDMI outputs, the options were limited to 24Hz per eye, which is enough for watching Blu-ray 3D movies, but too few for gamers.

For such tasks, they began to use the frame packing format, when the frames for the left and right eyes are combined into one, and the AMD Radeon HD 7970 supports the HDMI 1.4a frame packing format for outputting stereo images. This is the first graphics card with support for 3 GHz HDMI with frame packing, when each eye has a FullHD picture with a frequency of 60 Hz (120 Hz in total):

Another interesting novelty seems to us to be the Discrete Digital Multi-Point Audio (DDMA) multi-channel audio output technology, which works in conjunction with Eyefinity. All previous GPUs are capable of outputting only one audio stream via HDMI and DisplayPort. That is, even if three monitors located in different rooms are connected to the PC via HDMI, then only one audio channel is transmitted. But AMD Radeon HD 7900 received support for the simultaneous output of several independent audio channels at once, which may well come in handy in some multi-monitor configurations.

The same feature will be very useful for use in the field of video conferencing with multiple interlocutors displaying on separate screens, as well as multitasking applications such as playing on three monitors with game audio accompaniment and viewing news on a separate screen with an independent audio stream. Previously, for all this, you had to use several separate audio systems, but now everything works as conveniently as possible.

Eyefinity software support has not been forgotten either, the technology is updated almost every month - new opportunities appear. So, back in October, support for resolutions up to 16384 × 16384 appeared and new multi-monitor configurations: horizontal and vertical 5 × 1, as well as based on six monitors in 3 × 2 mode.

In the December video driver update AMD Catalyst Collaboration between Eyefinity and HD3D is now possible, and February promises to support custom resolutions, customize taskbar placement, and improve preset management.

Six monitors can be displayed using two DisplayPort 1.2 ports and two MST hubs (which we wrote about earlier), and three or even four monitors will require only one port and the corresponding hub. These hubs allow flexible configuration of the display system, they support up to four FullHD devices per DisplayPort 1.2 connector and should be on sale by the summer of 2012.

Speaking of resolution. High resolution or even ultra high - Ultra High Resolution. Current devices with a resolution of 4000 pixels on the larger side require connection using several cables at once: two DP 1.1 or four DVI. Monitors of this resolution of the next generation will be connected with only one cable: DP 1.2 HBR2 or HDMI 1.4a 3 GHz. And the new video card from AMD is already ready for such monitors, again it became the first in the world.

Video encoding and decoding

It is quite natural that the AMD Radeon HD 7970 includes the same UVD unit for decoding video data, which appeared in the previous generation of the company's video chips. It just doesn't need any improvements, supporting multi-stream MVC codec, decoding of MPEG-2 / MPEG-4 (DivX), VC-1 and H.264 formats, as well as decoding of two FullHD-streams in all supported formats.

AMD solutions provide the highest quality video stream decoding, use dozens of special algorithms to improve the quality and provide the best result in quality tests like HQV. Among the supported features, we note: color and tone control, noise reduction, sharpening, high-quality scaling, dynamic contrast, advanced deinterlacing, and inverse telecine. Here's an example of improving contrast on the fly:

But with decoding, all video chips have been more or less in order for a long time. All new GPUs provide decent quality and performance when viewing video data. But video encoding on the GPU is still in its infancy and the main complaints of users are directed to the low quality of the resulting compressed image.

Perhaps the new Radeon HD 7000 series will be able to help with this, because all GPUs in the series include a Video Codec Engine (VCE). The Radeon HD 7970 model became the first video card with support for hardware accelerated video encoding and compression using a specialized unit (previously, stream processors took part in encoding).

The quality and performance should be clearly better than before, with 1080p encoding supported at 60 frames per second, and even faster than in real time. It's hard to say anything about quality without tests, but we are promised different levels of encoder optimization for video data and games, as well as variable compression quality (the ability to choose between improving quality or performance).

So far, there is no place to try VCE - there are simply no applications that support it, but AMD is working with partners such as ArcSoft to provide support for VCE in their respective software products. A future video encoding acceleration software library is planned to make it easier for developers to support next-generation AMD products.

Encoding can be performed in two modes: full and hybrid (using the capabilities of GPU stream processors). Full Mode is designed for applications that require maximum energy efficiency and consistent performance levels. Full mode encoding on VCE is faster than real time and provides low latency. But there is also a hybrid mode:

In this mode, GPU math blocks work together with VCE. All well-parallelizable stages, which are highlighted in yellow in the diagram, can use the power of the GCN computational units, and the dedicated VCE unit is engaged in efficient hardware entropy coding. This mode is well suited for video cards with great mathematical power, such as the Radeon HD 7970. The question remains about the quality of these two modes, but this requires careful analysis in a separate article.

AMD Steady Video

In addition to video encoding and decoding, there is another area of application of the power of new graphics from AMD - improving poor quality handheld videos without the use of a tripod or other similar image stabilization tools. The video stabilization technology is called AMD Steady Video, and its second version has already been released.

The algorithm of the software stabilizer is quite simple: based on the video stream, statistics about the camera movement (shift, rotation, zoom) are collected and this movement is compensated for in the current frame, relative to the previous ones - the image is shifted, rotated and scaled so that the picture does not jump much and remains stable.

As simple as it is in words, it is just as difficult to implement. Just because there are two million pixels on the screen, and frames per second up to 30 or even 60. Imagine how many calculations need to be done to track all possible frame displacements. We have already written above about the QSAD function used in video processing, it is also used in Steady Video 2.0 to speed up the motion detection algorithm. So the GPU must handle random shifts with an amplitude of up to 32 pixels in any direction, and this requires a performance corresponding to more than 500 billion SAD operations per second (for 1920 × 1080 at 60 FPS).

Due to the support of new QSAD instructions in the Radeon HD 7970, its advantage over powerful CPUs in the motion detection algorithm exceeds 10x! That is, high-quality video will now be provided to us, and not only when processing home videos in video editors, but also when watching someone else's online videos, filmed by unknown means and unknown how.

Details: Radeon HD 7800 Series

Chip codename: "Pitcairn"
Manufacturing technology: 28 nm
2.8 billion transistors (slightly more than the Cayman, which is the core of the Radeon HD 6900 series)
Unified Array Architecture shared processors for streaming processing of numerous types of data: vertices, pixels, etc.
Hardware support for DirectX 11.1, including Shader Model 5.0
256-bit memory bus: four 64-bit controllers with support for GDDR5 memory
Core frequency: up to 1000 MHz (for Radeon HD 7870)
20 GCN computing units, including 80 SIMD cores, consisting of a total of 1280 ALUs for floating point calculations (integer and floating point formats, FP32 and FP64 precision support within the IEEE 754 standard)
80 texture units, with support for trilinear and anisotropic filtering for all texture formats
32 ROPs with support for anti-aliasing modes with the possibility of programmable sampling of more than 16 samples per pixel, including FP16 or FP32 framebuffer format. Peak performance up to 32 samples per cycle, and in Z only mode - 128 samples per cycle

Radeon HD 7870 Graphics Card Specifications

Core frequency: 1000 MHz
Number of universal processors: 1280
Number of texture units: 80, blending units: 32
Memory type: GDDR5
Memory capacity: 2 gigabytes
Maximum theoretical fill rate: 32.0 gigapixels per second
Theoretical texture sampling rate: 80.0 gigatexels per second.
One CrossFire connector
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, two Mini-DisplayPort 1.2
Power consumption: 3 to 175 W
Two 6-pin power connectors
Two-slot design
MSRP: $ 349

Radeon HD 7850 Graphics Card Specifications

Core frequency: 860 MHz
Number of universal processors: 1024
Number of texture units: 64, blending units: 32
Effective memory frequency: 4800 MHz (4 × 1200 MHz)
Memory type: GDDR5
Memory capacity: 2 gigabytes
Memory bandwidth: 153.6 gigabytes per second
Maximum theoretical fill rate: 27.5 gigapixels per second
Theoretical texture sampling rate: 55.0 gigatexels per second.
One CrossFire connector
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, two Mini-DisplayPort 1.2
Power consumption: 3 to 130 W
Two-slot design
MSRP: $ 249

And this time the principle of naming the company's products was not changed and the trends of the previous series were continued. The mid-budget series of video cards based on the GCN architecture differs from the top and budget lines by the second digit in the index: instead of 7 and 9, the number 8 is put, which is quite logical. Since AMD has taken the psychological 1000 MHz line for the GPU frequency, the Radeon HD 7870 has received a “GHz Edition” addition to the name, indicating that this frequency has been taken.

From the name it is clear that the Radeon HD 7800 is more productive than the HD 7700, but has a lower speed compared to the older models - HD 7900. As for the comparison with NVIDIA solutions, the older model HD 7870 at the time of release competes with the GeForce GTX video card 570, and the youngest is aimed at fighting the GTX 560 Ti, and NVIDIA has not released new mid-range 28 nm chips so far.

Both models of video cards from AMD have GDDR5 memory of the same volume of 2 gigabytes. They both use a 256-bit memory bus, so 1 GB, 2 GB, or 4 GB could fit on them. 1 GB is too little and 4 GB is too expensive for this price segment. Therefore, we can say that the ideal volume of 2 GB of video memory has been chosen, which is quite sufficient for the vast majority of games even at high resolutions, and not too expensive in terms of cost.

Otherwise, from the point of view of the consumer, the HD 7850 and HD 7870 are still different. The older Radeon HD 7870 has a higher power consumption, so it needs two additional 6-pin power connectors, and the HD 7850 is content with only one of them. Both boards have a dual-slot cooling system design, but most manufacturers produce boards with their own design, at least a cooler, or even a PCB.

Architectural Features of the Radeon HD 7800 Family

Above in the text, we have thoroughly described all the features of the new architecture Graphics Core Next (GCN), so we will repeat only the most important. All new graphics processors from the company offer excellent capabilities and performance not only in graphics processing, but also in non-graphics computing, including a mixture of different types of computing. Also, the new GCN architecture offers significant simplification of code optimization tasks, simplified development and maintenance, as well as stable and predictable performance and, in general, fairly high efficiency.

The basic building block of the new architecture is the GCN block, and all the GPUs in the Southern Islands series are assembled from them. Consider the block diagram of the Pitcairn chip:

The diagram shows the graphics processor Radeon HD 7870 (the "simplified" HD 7850 differs from it in several disabled blocks), we see 20 computing blocks of the GCN architecture. In the case of the junior solution of the Radeon HD 7800 series, four of them were disabled, and the number of active blocks in it is 16. This corresponds to 1280 and 1024 stream processors, respectively (just like in the case of the HD 7700 family, only there are exactly twice as many blocks) ... Since each GCN unit contains four texture units, the total number of TMUs for the older model is 80 TMUs, and for the younger model - 64 TMUs.

But the number of ROPs and memory controllers in the HD 7870 and HD 7850 also does not differ, as in the solutions of the youngest line. The number of ROP units was left quite high - 32 pieces for both models. The memory bus of motherboards based on Pitcairn has been cut down to 256-bit, it is assembled from four 64-bit channels. This is not bad for a solution of this level, although it is one and a half times less than in the top line, because the memory bus is traditionally cut down first. It is good that the use of fast GDDR5 memory gave a relatively high bandwidth of 153 GB / s.

Like the rest of the GCN architecture chips, Pitcairn includes a 9th generation tessellator block, featuring numerous buffering and caching optimizations, which significantly improve geometry processing performance. Here is a comparison of the new board from AMD with the solution of the previous generation in a synthetic problem, according to which we can assume an increase in the tessellation speed up to fourfold:

Likewise, many AMD technologies are supported, which have been implemented and improved in the new video chips of the Radeon HD 7000 line. Here is an incomplete list: PowerTune, ZeroCore, Eyefinity 2.0, HD3D, Steady Video, improved texture filtering quality, etc. All this is described in more detail above. Let's add to the list that the Radeon HD 7800 fully supports both the improved anti-aliasing algorithm MLAA 2.0 and supersampling anti-aliasing (SSAA).

As for the comparison of performance in games, the Radeon HD 7870 is significantly faster than its direct competitor GeForce GTX 570, especially given the lack of 1.25 GB of video memory in the latter (compared to 2 GB for the solutions in question) observed in modern games at high rendering resolutions ... The younger Radeon HD 7850 can be compared with the GeForce GTX 560 Ti, and here it can no longer boast of the amount of memory. Nevertheless, according to AMD's measurements, their new solution is still faster than the competing one in most games.

Details: Radeon HD 7700 Series

Chip codename: "Cape Verde"
Manufacturing technology: 28 nm
1.5 billion transistors (less than Barts, which is the core of the Radeon HD 6800 series)
Unified architecture with an array of common processors for streaming processing of multiple types of data: vertices, pixels, etc.
Hardware support for DirectX 11.1, including Shader Model 5.0
Core frequency: up to 1000 MHz (for Radeon HD 7770)
10 GCN computing units, including 40 SIMD cores, consisting of a total of 640 ALUs for floating point calculations (integer and floating point formats, FP32 and FP64 precision support within the IEEE 754 standard)
40 texture units, with support for trilinear and anisotropic filtering for all texture formats
Integrated support for up to six monitors including HDMI 1.4a and DisplayPort 1.2

Radeon HD 7770 Graphics Card Specifications

Core frequency: 1000 MHz
Number of universal processors: 640
Number of texture units: 40, blending units: 16
Memory type: GDDR5
Memory capacity: 1 gigabyte
Theoretical texture sampling rate: 40.0 gigatexels per second.
One CrossFire connector
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, two Mini-DisplayPort 1.2
Power consumption: 3 to 80 W
One 6-pin power connector
Two-slot design
MSRP: $ 159

Radeon HD 7750 Graphics Card Specifications

Core frequency: 800 MHz
Number of universal processors: 512
Number of texture units: 32, blending units: 16
Effective memory frequency: 4500 MHz (4 × 1125 MHz)
Memory type: GDDR5
Memory capacity: 1 gigabyte
Memory bandwidth: 72 gigabytes per second.
Maximum theoretical fill rate: 12.8 gigapixels per second
Theoretical texture sampling rate: 25.6 gigatexels per second.
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, One DisplayPort 1.2
Power consumption: 3 to 55 W
Does not require additional power supply
Single-slot design
MSRP: $ 109

An inexpensive series of video cards based on the GCN architecture differs from the top and middle lines by the second digit in the index: the 9th was taken by the number 7, as it was before. Radeon HD 7770 is a more productive solution, but there is also a younger model - HD 7750. At the time of its release, the older board had no direct competitors on the market, being located somewhere between the GeForce GTX 560 and GTX 550 Ti, and the younger one is aimed at fighting the GTX 550 Ti. For the HD 7770, a competitor was later announced in the person of the GeForce GTX 560 SE (all NVIDIA solutions are based on old GPUs).

Both models of AMD video cards under consideration have GDDR5 memory of the same volume of 1 gigabyte. Due to the use of a 128-bit memory bus, 2 GB could be installed on them, but such a volume of GDDR5 memory would be too expensive for their price segment. Therefore, so far, models with such a volume have come out, although in the future, variants with 2 GB of video memory may be released. In the meantime, they decided to leave this volume for the HD 7800.

In terms of other consumer characteristics, the HD 7750 and HD 7770 models are quite different. If the older Radeon HD 7770 has a two-slot design of the cooling system and its cooler is closed with a plastic casing like in older solutions, then the younger HD 7750 looks much simpler, occupying one slot and having a simple cooler. However, most manufacturers still produce motherboards with their own designs. The power consumption of new models in this price range is also different, the older one has one 6-pin additional power connector, and the younger one costs power from PCI Express.

Architectural features of the Radeon HD 7700

The basic block of the new architecture is the GCN block, and all the GPUs in the series are assembled from them. Each of the available GCN units is capable of scheduling and command distribution itself, and one computing unit can execute up to 32 independent command streams. Let's take a look at the block diagram of the Cape Verde chip:

The diagram shows the graphics processor Radeon HD 7770 (the "stripped-down" HD 7750 has several disabled blocks), we see 10 computing blocks of the GCN architecture. In the case of the junior solution of the Radeon HD 7700 series, it was decided to disable two of them, and the number of blocks became 8. This corresponds to 640 and 512 stream processors. And since each GCN unit contains 4 texture units, the total number of TMUs for the older model is 40 TMUs, and for the younger model - 32 TMUs.

The number of ROPs and memory controllers in the HD 7770 and HD 7750 does not differ, and the ROPs were decided not to be cut too much, leaving them in 16 pieces. But the memory bus at Cape Verde is cut down to 128-bit, which is assembled from two 64-bit channels. In general, this is three times less than in the top series, and we saw another confirmation that the memory bus is traditionally cut down in inexpensive chips first of all. Although the use of fast GDDR5 memory allowed leaving a relatively high (for such inexpensive solutions) bandwidth of 72 GB / s.

It remains for us to note the rather large amount of L2 cache - as much as 512 KB (compare with 768 KB for the top chip - apparently, the L2 cache does not take up too much space on the chip), as well as improvements in geometric performance. Like the top-end chip, Cape Verde has a 9th generation tessellator featuring numerous buffering and caching optimizations to significantly improve geometry performance over the Radeon HD 6000 series.

In general, we will not repeat all the information about AMD technologies that have been implemented and improved in the new video chips of the Radeon HD 7000 line (here is an incomplete list of them: PowerTune, ZeroCore, Eyefinity 2.0, HD3D, Steady Video, texture filtering quality improvements, etc.) .p.), all of this is written in more detail above. The HD 7700 series supports all of the features outlined there, including AMD Eyefinity 2.0 with six monitors and stereo rendering, and has an improved video decoding and encoding unit.

But what about the most important thing - performance in games? The first estimates of the rendering speed can always be made from the manufacturer's presentations. AMD believes that the Radeon HD 7770 is somewhere in the middle between the GeForce GTX 560 and the GeForce GTX 550 Ti, respectively, and compares it in its materials with the second model of the competitor.

But they do not compare the Radeon HD 7750 with anything, simply noting that most modern games are playable on this model at maximum settings in FullHD resolution. However, this is not surprising, since in recent years there are practically no PC-exclusives, and multi-platform games are much less demanding. So the Radeon HD 7700 series cards are perfect for undemanding users.

Details: Radeon HD 7790 Model

Chip codename: "Bonaire"
Manufacturing technology: 28 nm
2.08 billion transistors (more than Cape Verde in Radeon HD 7700, but less than Pitcairn in Radeon HD 7800)
Unified architecture with an array of common processors for streaming processing of multiple types of data: vertices, pixels, etc.
Hardware support for DirectX 11.1, including Shader Model 5.0
128-bit memory bus: two 64-bit controllers with support for GDDR5 memory
Core frequency: 1000 MHz
14 GCN compute units, including 56 SIMD cores, consisting of a total of 896 ALUs for floating point calculations (integer and floating point formats, FP32 and FP64 precision support within the IEEE 754 standard)
56 texture units, with support for trilinear and anisotropic filtering for all texture formats
16 ROPs with support for anti-aliasing modes with the possibility of programmable sampling of more than 16 samples per pixel, including FP16 or FP32 framebuffer format. Peak performance up to 16 samples per cycle, and in Z only mode - 64 samples per cycle

Radeon HD 7790 Graphics Card Specifications

Core frequency: 1000 MHz
Number of universal processors: 896
Number of texture units: 56, blending units: 16
Memory type: GDDR5
Memory capacity: 1 gigabyte
Memory bandwidth: 96 gigabytes per second.
Maximum theoretical fill rate: 16.0 gigapixels per second
Theoretical texture sampling rate: 56.0 gigatexels per second.
One CrossFire connector
PCI Express 3.0 bus
Connectors: DVI Dual Link, HDMI 1.4, two Mini-DisplayPort 1.2
Power consumption: 3 to 85 W
One 6-pin power connector
Two-slot design
MSRP: $ 149

An inexpensive video card model based on a new mid-budget chip differs from the previous top model of the HD 7700 subfamily by the third digit in the index: instead of 7, they put the number 9, which indicates an increase in performance. At the same time, the Radeon HD 7790 index clearly indicates that this is a less productive video card, compared to the line one step higher - HD 7800.

However, here, too, everything is not so simple - with the younger HD 7850, she will certainly be able to argue. But the recommended price of the Radeon HD 7790 is set at $ 149, that is, approximately halfway between the prices of the HD 7770 and the HD 7850. As for the solutions of a competitor from the same price segment, the release of the HD 7790 was clearly intended to have something to fight with NVIDIA GeForce GTX 650 Ti, based on the GK106 chip, which sits between the HD 7770 and HD 7850 in terms of price and speed. But NVIDIA immediately reacted to the release of the new motherboard by AMD, releasing an overclocked version of the GeForce GTX 650 Ti Boost, which is more powerful.

This model of the AMD video card has GDDR5 memory with a volume of only 1 gigabyte. The GPU has a 128-bit memory bus, and theoretically it would be possible to supply 2 GB, but this amount of fast GDDR5 memory is still too expensive for this price segment, and AMD released a model with a smaller volume, although in some modern games it may not be enough even at not the highest settings and resolutions. However, it is possible to release video cards from partners with 2 GB of video memory.

Like the models standing next to it in the lineup, the Radeon HD 7790 has a dual-slot design of the cooling system, which is covered with a plastic casing. Although most manufacturers still release motherboards with their own cooler design, the reference one is not that important. Interestingly, the power consumption of the new model did not increase too much compared to the HD 7770, but the improvement in energy efficiency was expected. By the way, that's why the new product also has only one 6-pin connector for additional power supply.

Architectural features

The new Bonaire GPU, on which the released Radeon HD 7790 is based, refers to the same Graphics Core Next (GCN) architecture that we have known for a year and a half, but AMD calls it GCN 1.1, hinting at small changes. In fact, the chip is architecturally practically the same from the previous ones, although there are indeed some minor changes. For example, the new architecture introduces instructions useful for Heterogeneous System Architecture (HSA), support for more concurrently executing threads, and a new version of AMD PowerTune technology, which we will talk about later. But all these changes cannot be called significant, because there is nothing new about the basic blocks and the improvement of their efficiency.

Therefore, we can safely refer to, which carefully describes all the features of the new architecture Graphics Core Next (GCN), and here we will only repeat the most important characteristics and features of a particular product. All of the latest AMD GPUs offer excellent features and performance in both graphics and non-graphics computing, including a mixture of the two. The new GCN architecture has also greatly simplified optimization and software development tasks while maintaining high efficiency.

As you know, the basic block of the architecture is the GCN block, from which all the GPUs of the Southern Islands series are assembled. Computing block GCN is divided into subsections, each of which works on its own flow of instructions. GCN blocks have dedicated 64KB local data storage for exchanging data or expanding the local register stack. The block also has a first-level cache memory with read / write capability and a full-fledged texture pipeline with sampling and filtering units. Each of the available GCN blocks is capable of scheduling and distribution of commands itself, and one computing unit can execute several independent instruction streams. Let's take a look at the block diagram of the new chip:

The Bonaire circuit confirms the goal of the new solution - to offer performance between Cape Verde, which has 10 GCN compute units, and Pitcairn, with its 20 GCN units. These two GPUs, released in 2012, differ from each other by almost exactly half, so there is a fairly large performance gap in the middle between them, which Bonaire has now filled.

The diagram shows a graphics processor in the form of a Radeon HD 7790, which is a complete solution without any block trimming. The chip includes 14 computing units of the GCN architecture, which corresponds to 896 stream processors. Since each GCN unit contains 4 texture units, the total number of TMUs for the new model is 56 TMUs. That is, Bonaire is exactly 1.4 times faster than the Cape Verde chip in terms of the speed of mathematical calculations and texture sampling, provided the frequency is equal.

But the number of ROPs and memory controllers in Bonaire and Radeon HD 7790 is similar to what we saw in Cape Verde and Radeon HD 7770 - they decided to leave 16 ROPs, and the memory bus of the new chip is 128-bit, assembled from two 64-bit bit channels. A small number of ROPs may be the "Achilles' heel" of the solution, since the use of fast GDDR5 memory made it possible to provide a relatively high bandwidth of 96 GB / s, but nothing can be done about the ROP performance.

But the new GPU has improvements in geometric performance and tessellation speed. Yes, Cape Verde also has a 9th generation tessellator, but Bonaire also doubled the number of geometry blocks, rasterizers and command processors (indicated as ACE in the diagram) - now there are two of them. This improvement gives Bonaire the ability to process up to two geometry primitives per clock, just like the more powerful Pitcairn and Tahiti.

As you remember, it was in the Radeon HD 7770 that AMD first took the important psychological boundary of the GPU clock frequency, equal to 1 GHz. So, the HD 7790 also has exactly the same reference frequency of 1 GHz, so the increase in performance compared to the HD 7770 will be justified solely by architectural changes and an increase in the number of execution units.

But the frequency of the video memory of the new product is much higher. While the HD 7770 had a relatively low memory frequency of 4.5 GHz, the HD 7790 is equipped with fast GDDR5 memory operating at 6 GHz, which provides a third more bandwidth. A 33% increase in video memory bandwidth over the Radeon HD 7700 subfamily has resulted in an understandable increase in gaming performance. AMD provides the following chart comparing the HD 7790's frame rates to memory running at 4.5 and 6.0 GHz:

The maximum memory bandwidth acceleration was achieved in games such as StarCraft II and Crysis 2. On average, 33% higher memory bandwidth gives somewhere around 10% increase in the average frame rate in a set of modern games. Not a bad indicator showing that memory bandwidth is quite important these days, although it is not the only focus for performance. Although it is quite possible that with more ROPs, the speed of the Bonaire would have been even higher ...

It is clear that the average power consumption has slightly increased compared to the HD 7770. If old model this value is 80 W, while for the HD 7790 it is 85 W - this is a very small price to pay for a theoretical increase in performance by 33-40%! Architectural improvements (PowerTune), design of a new GPU with experience from previous ones, as well as continuous improvement of the technical process at TSMC - all this led to a slight increase in consumption with a significant improvement in speed characteristics.

As for the chip area and the number of transistors in Bonaire, the new chip is clearly larger than Cape Verde, but the addition of computational, texture and geometric units could not pass without leaving a trace. According to these parameters, Bonaire is also located approximately in the middle between Cape Verde and Pitcairn. Bonaire contains 2.08 billion transistors in a 160 mm 2 chip, for Cape Verde these figures are 1.5 billion and 123 mm 2, respectively, and for Pitcairn - 2.8 billion transistors and 212 mm 2 chip area.

Naturally, the new chip supports all AMD technologies that have been implemented and improved in the new Radeon HD 7000 family (their list is incomplete: PowerTune, ZeroCore, Eyefinity, HD3D, Steady Video, texture filtering improvements, etc.), all this is written in detail in the article AMD Radeon HD 7970: The New Uniprocessor Leader. The HD 7790 supports all of the features outlined there, including AMD Eyefinity 2.0 with six monitors and stereo rendering, and has an improved video decoding and encoding unit.

Enhanced PowerTune Technology

Back in 2010, AMD introduced PowerTune technology in its Cayman chip (AMD Radeon HD 6900 series). This GPU was the first to introduce dynamic power management called PowerTune. It allowed us to increase the maximum clock speeds for typical applications, while avoiding too much power consumption in specialized stability tests such as FurMark. Then the technology was applied in the two-chip AMD Radeon HD 6990 model, which needed it even more for obvious reasons.

The technology received a major update in mid-2012, when an automatic boost was added to AMD PowerTune. In the AMD Radeon HD 7970 GHz Edition, this algorithm has improved performance even more than the regular version of the video card. The PowerTune algorithm for video cards without automatic overclocking uses three states: idle, low-load mode (low-3D), and full speed. The HD 7970 GHz also adds the Boost overclocking mode. PowerTune serves to stay within the required power consumption, switching to a lower load mode when necessary. In this case, the technology drastically reduces the clock frequency values. In practice, such jumps are rare because of the large gap between the two active modes.

Lowering the GPU clock speed reduces power consumption, but for more efficient control, you need to lower voltages as well. This is exactly what is done in the Radeon HD 7790. The new Bonaire graphics chip has eight states with different frequencies and voltages, which allows you to achieve higher clock speeds than before, while the GPU always operates at the optimal voltage and frequency. Switching between states is based on the GPU load, as well as the current power consumption of the video chip.

In the new algorithm, PowerTune does not have to drop the frequency sharply when the consumption level is exceeded, and along with the frequency, the voltage also decreases. The transitions between states should be as fast as possible so as not to exceed the consumption limit even for a short time, therefore Bonaire switches PowerTune states every 10 ms, that is, the state of the chip changes 100 times per second.

With such a constant change in frequencies, third-party applications such as MSI Afterburner and GPU-Z will not show instantaneous values of the clock frequency, but the average over a certain period of time - the so-called "effective" frequency. Another interesting innovation is that AMD is opening up new PowerTune settings for third party applications... Partners can also set their own PowerTune settings, which will help when creating factory overclocked graphics cards and provide more options beyond the reference values from AMD. True, different PowerTune settings can lead to the fact that video cards of the same model from different manufacturers will not only have different clock frequencies, but also the algorithm for changing them over time, which makes it difficult to compare under the same conditions.

Sales of video cards of the Radeon HD 7790 model on the market began at the very beginning of April 2013. AMD, together with its partners, organized the release of both motherboards with reference frequencies and factory overclocked solutions. And now both manufacturers are launching new video cards to the market in about the same way, with quick availability of various options from their partners. In fact, the partners released almost more overclocked versions of the HD 7790 than the usual ones, and the graphics chips in them operate at frequencies of the order of 1075 MHz.

Details: Radeon HD 7990 Model

Codename "Malta"
Manufacturing technology: 28 nm
2 chips of 4.3 billion transistors each
Unified architecture with an array of common processors for streaming processing of multiple types of data: vertices, pixels, etc.
Hardware support for DirectX 11.1, including Shader Model 5.0
Dual 384-bit memory bus: twice six 64-bit controllers with support for GDDR5 memory
GPU Frequency: 1000 MHz
Twice 32 GCN computational units, including 128 SIMD-cores, consisting of a total of 4096 ALUs for floating-point calculations (integer and floating-point formats, FP32 and FP64 precision support within the IEEE 754 standard)
2x128 texture units, with trilinear and anisotropic filtering support for all texture formats
2x32 ROPs with support for anti-aliasing modes with the possibility of programmable sampling of more than 16 samples per pixel, including in FP16 or FP32 framebuffer format. Peak performance up to 64 samples per cycle, and in Z only mode - 256 samples per cycle
Integrated support for up to six monitors via HDMI 1.4a and DisplayPort 1.2

Radeon HD 7990 Graphics Card Specifications

Core frequency: 1000 MHz
Number of universal processors: 4096
Number of texture units: 2x128, blending units: 2x32
Effective memory frequency: 6000 MHz (4 × 1500 MHz)
Memory type: GDDR5
Memory capacity: 2x3 gigabytes
Memory bandwidth: 2x288 gigabytes per second.
Maximum theoretical fill rate: 64 gigapixels per second
Theoretical texture sampling rate: 256 gigatexels per second.
One CrossFire connector
PCI Express 3.0 bus
Connectors: DVI Dual Link, four Mini-DisplayPort 1.2
Power consumption up to 375 W
Two 8-pin auxiliary power connectors
Two-slot design
The recommended price for Russia is 32,999 rubles. (for the USA - $ 999).

Already in the second generation of AMD video cards, the naming principle for two-chip models remains unchanged. The top solution based on two powerful video chips differs from the corresponding model of the previous generation by the first digit in the index: instead of 6, it received the number 7, indicating the series of new items. The announced video card differs from a single-chip solution in the third digit, which indicates the maximum performance within a generation.

As for the comparison with competitors, for the Radeon HD 7990 model announced today, the main rival is the GeForce GTX 690 video card, released almost a year ago, and it is these two-chip solutions that will have to fight each other. True, NVIDIA also has one more powerful solution, but based on a single GPU - GeForce GTX Titan, which can also be considered a competitor to the AMD motherboard in question.

The new dual-chip Radeon graphics card is equipped with 3GB GDDR5 memory for each GPU, which is due to the 384-bit memory bus of Tahiti chips. Such a volume is quite justified for a product of such a high level, since in some modern gaming applications, at maximum settings, anti-aliasing and high resolutions enabled, a smaller amount of memory (2 gigabytes per chip or less) may no longer be enough. And even more so, this applies to rendering in stereo mode or on multiple monitors in Eyefinity mode.

It is clear that such a powerful dual-GPU video card has a massive dual-slot cooling system, which differs from traditional coolers for AMD cards. It features a massive heatsink hidden under a shroud with three large fans operating at relatively low speeds. The power consumption of a card with two GPUs on board is quite high for obvious reasons, and it has two 8-pin power connectors, but at least that's not three, as was the case in non-reference samples based on two Tahiti chips.

Architecture

Since the video card codenamed "Malta" is based on two "Tahiti" GPUs from the Southern Islands family, you can simply refer to, which thoroughly describes all the features of the current Graphics Core Next (GCN) architecture. In the basic materials, we repeat only the most important characteristics and features of specific products.

The basic building block of the architecture is the GCN block, from which all the GPUs in the series are assembled. The computational unit is divided into subsections, each of which works on its own stream of instructions, it has a dedicated local storage for data, a first-level cache memory with read / write capabilities, and a full-fledged texture pipeline with sampling and filtering units. Each of the GCN blocks is capable of scheduling and distributing commands by itself, and one computing unit can execute several independent instruction streams. The Radeon HD 7990 uses two Tahiti chips we already know:

On the diagram of the graphics processor (there are two of them in the Radeon HD 7990), 32 computing units of the GCN architecture are visible and all of them are active. Previously, it was assumed that for a two-chip solution it would be necessary to disable some of them, and even lower the frequency in order to enter the 375 W power consumption limits, but AMD engineers managed to successfully solve this difficult task. Perhaps a special new revision of Tahiti was released with reduced power consumption, or the chips are simply going through a very tough selection.

Since each GCN unit contains 16 texture units, the number of TMUs is 128 units per chip, which gives a final performance of 256 gigatexels per second, which is very good for a competitor GeForce GTX 690. The number of ROPs and memory controllers in HD 7990 also did not change compared to the single-chip analogue, they were left in the amount of 32 and 6 pieces per GPU, respectively. The Radeon HD 7990 has a dual 384-bit memory bus built from twelve 64-bit channels, which provides a total memory bandwidth of 576 GB / s - another record figure.

Otherwise, the new board supports all modern AMD technologies that have been implemented and improved in the new Radeon HD 7000 video chips: PowerTune, ZeroCore, Eyefinity 2.0, HD3D, Steady Video, improved texture filtering quality, etc. All this is described in detail above in the description of the Radeon HD 7970, and there is simply no point in repeating it.

Cooling system and power consumption

In the case of such serious dual-chip motherboards, a highly efficient cooling system becomes especially important. If in the case of solutions from partners based on two Tahiti, three-slot solutions were used, and in the case of ASUS ARES II, even water cooling, in this case it was necessary to do with less forces, so a cooler was designed with a very massive radiator and three fans with improved acoustic characteristics.

The noise of the cooling system and the provided temperature for GPUs are among the most important consumer characteristics for any video card, including a top solution designed for enthusiasts. A too loud or ineffective cooling system will be regarded by buyers as a less profitable purchase, all other (approximately) equal indicators. So AMD approached this question in the case of the Radeon HD 7990 model very seriously when compared with other top solutions on the market. Consider the acoustic characteristics of the new system:

The diagram shows the noise levels from three different video cards: the Radeon HD 7990 and two competitors: the dual-GPU GeForce GTX 690 and the single-GPU GTX Titan from NVIDIA. Moreover, the noise was measured in different conditions - in idle mode (System Idle) and at maximum load using Furmark. If you believe the figures indicated by AMD, then even the single-chip Titan does not match their new product in terms of the noise level from the cooler, not to mention the dual-GPU GTX 690, which is the loudest in this comparison.

But weren't such impressive acoustics achieved to the detriment of the GPU temperature? The following chart shows GPU temperatures measured on AMD's Radeon HD 7990 and the same two competitors. This time, AMD only used the high load mode when testing with Furmark.

And again, a "tricky" coordinate axis is used with a nonzero origin. The real difference between 80 and 82 degrees for the Radeon HD 7990 and GTX Titan will be virtually imperceptible, although 87 degrees for the GTX 690 clearly stand out for the worse. Again, note that all of these tests were conducted by a stakeholder and are subject to independent verification.

In terms of power consumption, the dual-chip solution is nothing new, but support for the previously announced ZeroCore Power technology is also there. This technology helps to achieve significantly lower power consumption in "deep idle" (or "sleep") mode with the display device turned off. In this mode, an idle GPU is almost completely turned off, and consumes less than 5% of the power of a full-fledged mode, turning off most of the functional blocks. And in the case of a two-chip board, it is even more important that in the CrossFire system, when drawing a two-dimensional interface of the operating system, all GPUs, except for the main one, do not work at all. That is, in the case of the Radeon HD 7990, one of the chips in 2D mode will be immersed in a deep sleep with minimal power consumption, and the second one can "fall asleep" in the deep idle mode of the PC.

This AMD Radeon HD 7800 Series graphics card has 800 megahertz processor frequency. High productivity and the bandwidth (153 gigabits per second) is provided by a 256-bit bus. Computing system processes data equal to 1.76 teraflops. Computing units are present in the amount of 16 pieces, and texture units - in the amount of 64 pieces. There are two cores for computing processes.

The memory format complies with the GDDR5 marking, and support for DirectX version 11 will help accelerate interaction with applications of the operating system. For the best optimization of the card's performance, you need to keep an eye on the driver updates, since only they are able to fully reveal all the capabilities of the GPU and provide access to the necessary settings. Basic drivers, which designate the video card in the system, are included with the card, and the updated version can be viewed on the AMD website.
This AMD Radeon HD 7800 Series GPU comes with the latest on-board technologies to deliver smooth, 60-frame images with resolutions up to 4096 x 2160 pixels. The same applies to the audio stream, which meets all modern requirements, giving out high-quality sound.

Radeon 7870

This AMD Radeon HD 7800 Series graphics card is a powerful successor of the previous card in terms of characteristics. She has a whole gigahertz at her disposal to work with the GPU. Performance for computational operations is much higher than in the previous version - 2.56 teraflops. There are 20 computational units and 80 texture units.

Since this is the flagship of the 7800 series, it surpasses its counterpart in many ways. Support for tessellation technology has been introduced into video cards of this manufacturer for a long time, but in this version it has been pushed to the limit. Now you can enjoy three-dimensional images that are striking in their realism and detail. And improved anti-aliasing will help you achieve a smooth and pleasing picture.
In other parameters, this representative AMD Radeon HD 7800 Series in terms of characteristics completely coincides with the previous video card. Both cards are capable of supporting 3D technology in both video and games. It is also possible to connect to improve the performance of multiple cards, but this parameter may also depend on the capabilities of the motherboard.

Page 2 of 5

"South Islands"

First, a little about AMD's labeling of its latest products. The manufacturer has divided them into three levels according to performance. The codename "Cape Verde" refers to the Radeon HD 7700. The name "Pitcairn" hides today's test takers, the Radeon HD 7870 and HD 7850. The high-end products are called the "Tahiti" or the Radeon HD 7900. This is shown more clearly below.

Entry Level = Cape Verde = Radeon HD 7700 Series;
Mainstream = Pitcairn = Radeon HD 7800 Series;
High Performance Products = Tahiti = Radeon HD 7900 Series.

That is, at the moment, AMD has covered all market segments with their 28 nm graphics chips. Only the release of a dual-core video card based on Tahiti chips is expected. The tentative name is Radeon HD 7990.

Features of the AMD Radeon HD 7800 Series

The graphics processor Radeon HD 7800 (Pitcairn) has about 2.8 billion transistors and the Graphic Core Next microarchitecture. As mentioned above, the Radeon HD 7850 (Pitcairn Pro) chip has 16 computing units, and its maximum TDP is 130 watts. For the Radeon HD 7870 (Pitcairn XT), these figures are 20 and 175, respectively.

The slide below shows the main specifications of the Radeon HD 7850 and HD 7870 video cards

2GB GDDR5 memory is already becoming the standard for most mid to high end models. Thanks to 256-bit. bus and a high clock frequency of 1200 MHz (4800 MHz effective) bandwidth is 154 GB / s. This will have a positive impact on performance in high-definition games and picture quality.

PCI Express 3 interface

In the second half of 2011, almost all motherboard manufacturers presented their motherboard models with the 3rd generation PCI Express interface. With the release of the Radeon HD 7000 series, video cards with this interface appeared. PCI Express 3 has twice the bandwidth (32 Gb / s) than the previous generation PCI Express. Compared to PCIe 2, the bandwidth on each lane has been doubled from 500 MB / s to 1 Gb / s.

Naturally, to take advantage of the new PCIe 3, you need not only a video card and a motherboard with this interface, but also support from the processor (from the Ivy Bridge family, not all models will support PCIe 3).

Eyefinity 2.0

AMD has gone further with its Eyefinity technology, which is designed to display images across multiple monitors. Thanks to the high processing power of the HD 7000 series and support for Eyefinity 2.0, it is now possible to display an image with a total resolution of 16000 x 16000 on multiple monitors. This allows you to display the image on 5 displays with a resolution of 2560x1600 installed in landscape orientation. To work with such resolutions, a record 3 GB GDDR5 (HD 7970 and HD 7950) is installed on the older models of the family.

AMD Catalyst drivers will support custom resolution starting in February. That is, you can set the required resolution depending on the configuration of the displays in Eyefinity. As of Catalyst 12.2, there is an option to install the Start menu on a convenient display, not on the far left, as it was before. In addition, Eyefinity 2 supports HD3D stereo image output. Combination of three monitors that work in 3D mode is supported.

Improved tessellation

AMD's Radeon HD 7000 family of graphics cards feature a ninth generation tessellator and have seen significant performance gains in geometry processing in modern games. The core of GCN still includes two Graphics Engines, but if earlier they contained blocks for tessellation and rasterization, now they consist of an arbitrary number of pipelines designed to process geometry and pixels.

AMD Radeon HD 7800 graphics cards support HDMI 1.4a, which allows you to display a picture of 120 Hz (60 Hz per eye), which allows you to display 3D images. With earlier versions of HDMI, this was not possible. Starting in December, AMD included HD3D and Eyefinity interoperability in their drivers.

DirectX 11.1

Video cards of the Radeon 7000 family will support the upcoming DirectX 11.1. It is too early to say what this will give in practice, since DX 11.1 will be released alongside Windows 8. The main advantages of the new API are indicated as follows:

Independent rasterization;
Flexible combination of graphic computing and video processing;
Native Stereo 3D support.

AMD Unified Video Decoder

It is the hardware part of AMD GPUs responsible for decoding the video stream. The Radeon 7000 UVF series has received some enhancements. In general, UVD has retained all the functions of its predecessors, namely support for H.264 / AVCHD, MPEG-2, MPEG-4 / DivX, VC-1 / WMV profile D, Multi-View Codec (MVC), Video Codec Engine ( VCE), AMD Steady Video 2.0. Added support for Dual Stream HD + HD format.

Modern games every year require more and more powerful video cards for graphics processing. One of the budget solutions for gamers will be the AMD Radeon HD 7800 Series. Consider the technical characteristics of this series, as well as its features and performance in games.

Consider the characteristics of the AMD Radeon HD 7800 Series in the form of a table:

Technical process	28 nm
GPU	Pitcairn
GPU	Frequency (min.max.on models)	800-1000 MHz
RAM	Type of	GDDR5
	Volume	2 GB
	Frequency	800-1200 MHz
	Bandwidth	153.6 GB / s
Interfaces	Memory capacity	256-bit
Interfaces	Bus type	PCI Express 3.0
Architecture	GCN
	Stream processors per block	from 64 to 80
	Number of blocks	from 16 to 20
	Stream processors total	1024-1280
	Cores for geometry processing	2 pcs.
	Cores for asynchronous computing	2 pcs.
Connectors	HDMI Display Port 1.2
Supported technologies and software	DirectX 11	Yes
	OpenGl 4.2	Yes
	Eyefinity (monitor fusion)	up to 6 pcs.
	ZeroCore Power	Sleeping mode
	Catalyst	Branded Drivers and Settings
	App Acceleration	Improving video playback quality
	AMDHD3D	3D graphics processing
	Power tune	Dynamic setting energy consumption

The line was produced in March 2012. The following models were released on its basis:

HD7850;
HD7870;
HD7890.

At the moment, the lineup is no longer available. At the start of sales, the average price in stores was $ 249 and $ 349.

Overview

At AMD, after entering a new technical process, it was decided to divide the general production series into subgroups. Therefore, on the basis of the 28nm technical process, 4 lines were formed, which are presented in the table:

The HD 7800 with a Pitcairn GPU uses the Graphic Core Next microarchitecture. The series was launched in March 2012 and is no longer in production today.

At one time, video cards from Pitcairn were quite popular and showed an excellent price / quality ratio. For 2018, the current series is not popular and it is extremely difficult to find a device in a new state. Despite the fact that the graphics core is already outdated, in an assembly with a powerful processor, a PC can handle various games at medium and high settings.

What games will go to AMD Radeon HD 7800 Series

Graphics cards were released back in 2012, but they can still be used on modern toys. Tests in games AMD Radeon HD 7800 Series were carried out with the following hardware:

Processor: Core I5 6500 3.2 GHz.
RAM: 16 GB DDR4 2133 Dual.
Hard drive: Hitachi 1TB.
Motherboard: Asus H170M-Plus.
Resolution: 1920x1080px.

The results are as follows:

Name of the game	Graphics quality
Assassins creed syndicate	Hight	31
WarThunder	Cinema (Ultra)	55-65
Quantum Break	The average	30-42
Assassins Creed Unity	The average	30
Shadow warrior 2	High	35-45
Dying light	High	40-50
Fallout 4	Ultra	38-43
GTA 5	Above the average	45-50
DOOM	High	40
Rise Of The Tomb Raider	High	30-40
Warface	High	90-100
The Witcher 3: Blood and Wine	High	25-35
World of tanks	High	60-80

Overall performance is highly dependent on the correct combination of processor and graphics card. If you take a powerful modern generation processor like Ryzen or Core I5, then they will be able to show high FPS in most modern games, even with an old video card.

After analyzing the technical characteristics and tests in games, we come to the following conclusions: it is not recommended to buy for powerful games in 2018, it is better to choose a newer model.

The performance will be enough for comfortable homework and for running multiplayer toys like CS: GO, World Of Tanks.

How to overclock a video card

To get the best performance, you can overclock your AMD Radeon HD 7800. To do this, you will need to install and configure the driver.

The main changes need to be made in the "Games" section. If you use a modern driver, the profiles can be customized for each video game.

Go to the desired profile for the "Frame rate control" setting. By default, the video card squeezes out the maximum FPS and spends all the resources on it.

For a comfortable game of shooters, 60 frames per second is enough. For CS: GO, WarFace, WarThunder, it is enough to set the limit at 70 FPS.

The OverDrive setting allows you to adjust the operating parameters: the frequency of the GPU and memory, the efficiency of the fans and the level of power consumption. These parameters must be configured individually for each PC build.

Download drivers for AMD Radeon HD 7800 Series

To download drivers for Radeon HD 7800 Series, use the proprietary autosearch program. You can download it on the official website of the manufacturer. There you can also find drivers for each OS version: Windows 7, Windows 10, etc.

AMD has officially unveiled a new series of video cards based on the 28nm GCN microarchitecture - AMD Radeon HD 7800... At the moment, it includes two models: and. The new items are based on the AMD "Pitcairn Pro" and AMD "Pitcairn XT" graphics processors, which operate at a clock frequency of 860 MHz and 1000 MHz, respectively. Thus, the video card will become the second in the company's lineup (after AMD Radeon HD 7770) with the name "Ghz Edition".

The solution is equipped with 16 computing units, 1024 stream processors, 64 texture units and 32 ROP units. The video subsystem of the novelty is made up of 256-bit chips of the GDDR5 standard with a total capacity of 2 GB. Their nominal clock frequency is at 1200 MHz, and their effective clock is 4800 MHz.

The external interfaces of the model include four ports: DVI, HDMI and two miniDisplayPort.

The graphics adapter has a better structure, which includes: 20 computational units, 1280 stream processors, 80 texture units and 32 ROP units. The video subsystem of this novelty, as well as the set of its external interfaces, is identical to the model.

Mass sale of solutions and starts on March 19. The recommended retail price for these new products will be $ 249 and $ 349, respectively. Comparative table of technical specifications of new series video cards AMD Radeon HD 7800 looks like this:


Production process standards, nm
Microarchitecture
GPU		AMD "Pitcairn Pro"	AMD "Pitcairn XT"
	Clock frequency, MHz
Number of computing units
Number of stream processors
Number of texture units
Number of ROPs
Video memory
	Volume, GB
	Nominal clock frequency, MHz
	Effective clock frequency, MHz
	Bus width, bit
Internal interface		PCI Express 3.0 x16
External interfaces		1 x DVI 1 x HDMI 2 x miniDisplayPort
Estimated price, $
Supported instructions and technologies		DirectX 11.1, DirectCompute 11, OpenGL 4.2, OpenCL 1.2, AMD Eyefinity, AMD CrossFireX, AMD HD3D, AMD PowerPlay, AMD PowerTune, AMD Eyespeed, AMD ZeroCore

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