Feeding phases - quantity, practical benefit from quantity. Power phases for the processor on the motherboard - how much do you need? What kind of power supply is needed for a modern gaming pc Number of processor power lines

Common parameters:

Release year- Year of the first release of the model motherboard... This type of equipment is characterized by a long production period from the date of the year of release.

Type of- The motherboard ensures the interaction of all components, both unified system managing their teamwork. All other computer components are installed on it or connected to its connectors.

Model- The name of the product from the manufacturer. Consists of the name of the brand (brand), series and article. The series indicates a group of goods, the article is an abbreviation that abbreviated the main functions and properties of one particular device.

For gaming computer - The motherboard has a set of necessary characteristics to play modern games.

Form factor and dimensions:

Form Factor- Form factor of the motherboard.
The form factor determines the dimensions, mounting holes, motherboard power connectors, and cooling requirements. When choosing components for a computer, you must remember that the computer case must support the form factor of the motherboard. Possible motherboard form factors: ATX, microATX, EATX, BTX, mBTX, mini-ITX

Height- The distance from the bottom edge of the product in vertical position to the top edge, where the processor socket is usually located.

Width (mm)- Distance from the left edge, where the rear panel with connectors and expansion slots is located, to the right edge, on the side of the memory and SATA connectors.

CPU:

Socket- The type of connector into which the central processor is installed.

LGA 1151-v2- Only 8th and 9th Gen Intel Core series processors are compatible with LGA 1151-v2 motherboards.

For processors- Manufacturer of the processor supported motherboard... Choosing a motherboard usually starts with choosing a processor manufacturer: as a rule, a motherboard supports several processor models from the same manufacturer, and over time you can replace your processor with a more powerful one. Today, the main manufacturers (and competitors) of PC processors are Intel and AMD.

Embedded processor model- The characteristic indicates the series and model of this processor, as well as the number of processing cores and their frequency.

Integrated central processing unit- Some motherboards of a certain form factor come with a soldered central processor.

Chipset:

Number of cards in SLI / Crossfire- SLI and CrossFire technologies allow combining the power of several video cards installed on one motherboard. Most often we are talking about the joint use of two video cards, but it is also possible to connect three or four graphics cards simultaneously. This can significantly improve system performance, which can help solve complex graphics problems. The performance gain occurs only when working with applications that can use the power of several video cards simultaneously. However, this significantly increases the power consumption of the computer, the need for cooling, and the noise level. To connect, you must have the appropriate number of PCI-E slots on the motherboard, as well as support by the motherboard for SLI or CrossFire technology. You also need a fairly powerful power supply (at least 550 watts), it is best to use the ones recommended by the manufacturers GPUs Power supplies. SLI technology uses NVIDIA company, CrossFire - AMD (ATI). To connect using the SLI technology, you need to use the same video cards with SLI support, and for connecting using the CrossFire technology, it is enough that the video cards belong to the same series.

UEFI- EFI is software interface allowing you to associate operating system with internal programs of PC components, which is intended to replace standard BIOS... EFI has graphical interface, full support for the mouse, as well as the ability to work with hard drives larger than two terabytes.

Chipset- Chipset - the center of the motherboard, the point where all the interface buses of the components connected to the motherboard are connected. It is also the link between most of the PC nodes with the central processor.
In modern computers, the chipset is no longer as important as it was in the early years. For example, the graphics core of the integrated video accelerator has already moved to the central processor, controller random access memory did it even earlier. Gradually, various blocks and parts of the chipset will be integrated into the CPU more and more intensively.

BIOS- BIOS (Basic Input / Output System) is a special firmware written in flash memory that is executed first when the computer is turned on. The BIOS checks the entire system and is also responsible for configuring the components installed on the system. Advanced users can use BIOS features to fine tuning system or overclocking of individual components. Major BIOS manufacturers: Award, Phoenix, Ami.

SLI / CrossFire support- Support for parallel operation of multiple video cards on the motherboard.
Possible options for this technology: CrossFire, SLI, 3-way SLI, CrossFire X, Hybrid SLI, Hybrid CrossFireX.
NVIDIA SLI technology and ATI CrossFire technology combine the processing power of two cards installed on one motherboard. Usually, such a construction of a video system is used by fans of three-dimensional games, for which the power of one video card is not enough.

Memory:

Maximum memory size- The maximum amount of memory supported by the motherboard is also required to support this amount by the processor, the memory modules are usually selected the same, when installing different ones, there may be problems in the operation of the system.

Number of memory channels- The number of memory channels in this unit.
To improve the speed performance of the memory subsystem, memory controllers are used that work in parallel, which allows you to increase the theoretical throughput.

Number of memory slots- The number of memory slots installed on the motherboard.
The more slots on the board, the more memory modules can be installed on it. The presence of free slots is convenient in many cases. For example, if you have free slots, then when upgrading the system, you buy additional memory modules and install them in the free slots, while the old modules also remain in their places.

Minimum memory frequency- The minimum frequency of RAM supported by the motherboard.

Maximum memory frequency (MHz)- The maximum frequency of RAM supported by the motherboard. The higher the frequency of the RAM, the greater its bandwidth and the higher the overall system performance.

Supported memory type- The computer's RAM is a type of DRAM - volatile random access memory. DRAM is divided into subtypes (different versions of DDR memory), which differ in both the slot and the data transfer rate (the speed increases with each generation). To support a specific type of memory, an appropriate controller is required, so different types memories are not compatible with each other. Type determines internal structure and the main characteristics of memory.

ECC mode support- Algorithm for automatic detection and correction of errors that occur during the operation of RAM. Correction is possible if the transmission violation has affected no more than one bit in a byte. ECC technology is supported by most server motherboards, as well as some motherboards workstations. For the algorithm to work, it is necessary to use special memory modules with ECC support.

Supported memory form factor- RAM is divided into mobile (SODIMM) and for ordinary PCs (DIMM), so be extremely careful when choosing!

Storage controllers:

Number of M.2 slots- Was created as a replacement for the mSATA format, which used the physical connector and dimensions of PCI Express Mini Card modules. The M.2 standard allows for a wider variety of module sizes, both in width and length. The M.2 format is better suited for performance solid state drives (SSD), especially when used in compact devices.

SATA Express ports quantity- The number of SATA Express ports on the motherboard. SATA Express originally appeared as part of SATA 3.2, an enhanced version of SATA 3. Main feature This interface is a combination of the SATA standard with the PCI-E bus (see below), so that drives using any of these technologies can be connected to SATA Express. In the first case, the connection speed will correspond to the original version 3 - 6 Gb / s, while two standard SATA connectors are placed in one SATA Express port at once. When working with PCI-E, the speed will depend on the version of this bus.

MSATA connector- The characteristic indicates the presence or absence of an mSATA connector on this motherboard.
mSATA (Mini-SATA) is a solid state drive form factor measuring 50.95 x 30 x 3mm, supports devices that require small SSD drives... The mSATA connector is similar to the PCI Express Mini Card interface, they are electrically compatible, but require some signals to be switched to the appropriate controller.

Number of U.2 slots- U.2 can be considered a variant of M.2, designed for cable connection of drives of the 3.5 or 2.5 inch size. The connector is slightly narrower than M.2, but has the same pin count and bandwidth (up to 32 Gbps when using the PCIe protocol).

Type and number of SATA ports- Type and number of SATA connectors, allow you to connect hard drives, SDD and optical drives with this interface.

M.2 Form Factor- The form factor determines the size of the M.2 drive, which is installed on an expansion card installed in a PCI-Express slot, or on the motherboard itself. All M.2 SSDs have a recessed M.2 slot. This form factor provides maximum performance with minimal resource consumption.

NVMe support- Availability of NVMe support. NVM Express is a specification for access protocols for solid state drives(SSD), connected via the PCI Express bus. This designates volatile memory (NAND flash memory). A new set of instructions and a queuing mechanism allows you to optimize work with modern processors.

IDE controller- Type of IDE controller installed on the motherboard.
IDE (Integrated Drive Electronics) is a parallel data transfer interface that until recently was the standard connection interface hard drives v personal computers... Currently at connecting hard drives instead of IDE, SATA is more often used, but IDE is still widely used when connecting optical drives(CD / DVD).

SATA RAID Operation Mode- The characteristic indicates the mode of operation of SATA RAID in this motherboard.
RAID is an array of several disks (storage devices) controlled by the controller, interconnected by high-speed data transmission channels and perceived by the external system as a whole. Depending on the type of array used, it can provide different degrees of fault tolerance and performance. Serves to improve the reliability of data storage and / or to increase the read / write speed.

Expansion slots:

Number of PCI slots- The number of PCI slots installed on the motherboard.
PCI, local connection bus peripheral devices- remains the most popular bus for connection additional cards extensions. The more PCI slots on the motherboard, the higher the potential for expanding the capabilities of your computer. In free PCI slots, you can additionally install network card, modem, sound card, TV tuner, Wi-Fi adapter, etc.

Number of PCI-E x1 slots- The number of PCI-E x1 slots installed on the motherboard. This characteristic indicates the physical standard size of the slot.

Number of PCI-E x4 slots- The number of PCI-E x4 slots installed on the motherboard. This characteristic indicates the physical standard size of the slot.

Number of PCI-E x8 slots- The number of PCI-E x8 slots installed on the motherboard. This characteristic indicates the physical size of the slot.

Number of PCI-E x16 slots- PCI-E is a high-speed serial bus used as slots for various expansion cards. In particular, the full x16 version is used to connect video adapters. This characteristic indicates the physical size of the slot.

Modes of operation of several PCI-E x16 slots- Each number represents a PCI-E slot and the number of dedicated data lines for it. For example, consider 16-0-0, 8-8-0, 8-4-4:
16-0-0 means that one video card is installed (in the first slot), the video card communicates with the controller via 16 lines. The remaining two slots are empty.
8-8-0 set two cards. Each is given 8 lines.
8-4-4 - three cards. Accordingly, the first is assigned 8 lines, the rest four.

PCI Express version- Feature indicates the version of the serial PCI bus Express installed in this motherboard.
It should be noted that different PCI-E versions are compatible with each other.

Rear panel:

Number of network ports (RJ-45)- Ethernet port for connecting a computer to local network... Any motherboard has an integrated network controller designed to connect network cable with RJ-45 connector. Such a controller is capable of providing a network with a speed of 10/100 Mbit / s, although controllers with a speed of 100/1000 Mbit / s of the Ethernet 802.3 network standard ( wired network). Motherboards are available with two integrated network controllers.

Internal USB connectors on board- The characteristic indicates the number of USB connectors on this motherboard.

Number and type of USB on the back- The characteristic indicates the number and type of USB ports on the rear panel of this motherboard.

PS / 2 ports- Availability of a PS / 2 interface for connecting a keyboard / mouse.
Until recently, PS / 2 was the standard interface for connecting to a computer, but modern keyboards / mice are often equipped with a USB interface, so this connector may no longer be found on new motherboards.

Connectors for connecting information output means.

1x Mini DisplayPort

Digital audio ports (S / PDIF)- The characteristic indicates the presence or absence of digital audio interfaces on this motherboard.

Audio:

Sound adapter chipset- The characteristic indicates the chipset (chipset) of the sound adapter integrated (installed) on this motherboard.

Sound- The type of sound controller installed on the motherboard. There are three main types of sound controller: AC "97, HDA, DSP.

Sound scheme- Supported sound scheme (number of sound channels). Modern motherboard sound controllers support virtually all existing surround sound systems. On many motherboards, to configure 7.1 channel audio, you must use the front audio module and enable the multi-channel audio feature in the audio driver.

Network:

Chipset network adapter - The characteristic indicates the chipset (chipset) of the network adapter integrated (installed) on this motherboard.

Network adapter speed- The characteristic indicates the maximum baud rate of the network adapter installed on this motherboard.

Built in wifi adapter - Wi-Fi - wireless means of communication that allow you to connect a PC to a local network and the Internet.

Bluetooth- Bluetooth, wireless interface used in many mobile devices.

Cooling:

3-pin connectors for system fans- Special connectors for cooling fans. Two connectors are responsible for power supply (plus, minus), and the third transmits information about the speed of rotation of the impeller.

4-pin connectors for system fans- Special connectors for cooling fans. Unlike 3-pin, they have a control wire for the built-in PWM controller, which allows the computer to smoothly control the fan speed depending on the temperature of the components inside the system unit.

CPU cooler power connector- The type of connector for the fan cooling the central processor.

Nutrition:

Number of supply phases- The number of lines of the voltage converter responsible for power supply central processing unit... The more lines, the more power that the CPU power system can handle, which allows processors with higher power consumption to be installed or overclocked.

Processor power connector- The type of connector for powering the processor, the power supply must have similar connectors or adapters must be used.

Main power connector- The type of main power connector installed on the motherboard.
Possible values: 20-pin, 24-pin, 18-pin. The power connector is used to connect the power supply to the motherboard. To choose the right power supply, you need to take into account the type of connector installed on the motherboard. New motherboards usually have a 24-pin connector, older models have a 20-pin connector.

Extra options:

Features, optional- Information about the motherboard that is not included in the other specifications.

Equipment- The complete set of delivery is indicated (except for the main product).

LPT interface- Availability of the LPT interface on the motherboard.
The parallel LPT connector (usually D-Sub 25-pin) will allow you to connect a printer or other LPT-enabled devices. Now there are fewer and fewer devices with a parallel LPT interface; therefore, support for the LPT connector on the motherboard is not required.

Illumination of board elements- Decorative lighting of individual elements on motherboards.

Now let's move on to an equally important part of any PC - the motherboard.

1. The color of the motherboard is important, and it is best to take black

A funny myth with a very simple history: large vendors such as Apple or Asus began to paint their expensive motherboards black about 10 years ago. Of course, they broke less than simpler "color" motherboards from competitors, hence the belief that "black goez fasta" came from. In fact, the color of the board can be absolutely any - yellow, green, white, blue, black - because this is a banal painting that does not in any way affect the internal characteristics of the PCB. So, for example, in the 90s, textolite was often not painted at all, and most of the boards - both expensive and cheap - had a dirty yellow color. So the difference between black and white boards is exactly the same as between black and white iPhone - only in color and nothing more.

2. Heating the processor power circuits up to 90 degrees is a critical lot

Mosfets are highlighted in red - the hottest elements of the CPU power supply circuit.

Do not confuse the processor itself and its power supply circuits - indeed, for silicon CPUs, temperatures above 90-100 degrees are critical and will lead to its rapid failure. But this is not true for power circuits: so, the hottest part of them - the so-called mosfets (field-effect transistors with an insulated gate) - have operating temperatures up to 150-175 degrees, so 90 degrees on them, of course, is a lot, but not critical. All other elements of the power circuits, such as capacitors and chokes, heat up seriously less and are often not covered by radiators at all because of this.

3. Internal peripherals on boards are always of low quality and need to be bought separately

A myth that goes back almost from the bearded 90s, when sound and network controllers on boards really left much to be desired. However, now this is not the case for a long time: 99% of boards are equipped with gigabit LAN controllers from Intel or Realtek, and taking into account the fact that the speeds home internet on average, an order of magnitude lower, there will be no problems with them.

With the sound, everything is a little more serious - now the boards are mainly equipped with controllers from Realtek. Calling them audiophile language does not turn out, but if you listen to music from streaming services and play games, there will definitely be no problems with sound quality.

4. Any expensive motherboards with a bunch of ports and heatsinks are not needed, since even the cheapest solutions based on the Z370 chipset support my Core i9 - I'll choose from them

Of course, there is always a desire to save money, and you can often take a cheaper board without, for example, built-in Wi-Fi or m.2 slots, saving up to a couple of thousand rubles. But, alas, further savings usually begin to affect the circuitry of the board - namely, manufacturers begin to reduce the number of CPU power phases on the board from 6-10 to 3-4. Why is it scary? If earlier the energy required to power the processor passed through 10 phases, heating them not very much, now it will pass through only 3 phases, which will increase the heating significantly. Plus the fact that cheap motherboards often do not even have the simplest radiators on the power circuits, they can easily heat up to 120+ degrees with top processors under load, which is already critical for them:

In addition, various negative effects begin: for example, overheating protection may work, which will reduce the voltage on the processor, which means its frequency and performance. Weak power circuits may initially not provide the voltage necessary for the top processor to work under load, which again will negatively affect its frequency. So, alas - cheap motherboards are better left for simpler processors.

5. For top-end PCs, it is better to take full-size boards

The myth again comes from the beginning of the 2000s, when compact motherboards began to appear - then manufacturers, in pursuit of sizes, could really seriously curtail the functionality of such motherboards. But now this is not the case - of course, mini-ITX boards have only one PCIe x16 slot and usually two slots for RAM, but all other parameters - even the ability to overclock processors and an m.2 slot with NVMe support - may be present, so there are no problems to assemble a top-end PC with Core i9-9900K and RTX 2080 Ti in a case with dimensions that are slightly larger than those of consoles.

6. Reinforced PCIe slots and RAM - marketing, they are not needed

In the past few years, various manufacturers have begun to reinforce PCIe slots and even RAM, justifying this by the fact that modern top-end video cards often weigh 1.5-2 kg, which can break the slot. However, here you need to understand a couple of things: firstly, this does not answer the question of why to reinforce the RAM slots, since even with heatsinks the dies hardly weigh more than a couple of hundred grams and will definitely not break the plastic in any way. Secondly, upon closer inspection, it will be seen that the slot reinforcement on the board itself does not touch, that is, the slots are still held only on their own contacts:

I think you're under the impression that I'm contradicting myself and arguing that reinforcement is really marketing. However, this is not entirely true: in reality, under the weight of a heavy video card, the narrow slot of the plastic PCIe slot may expand slightly, which will cause contact to be lost. Reinforcement will prevent this from happening - but, again, if you have a heavy video card, you should buy a special holder so as not to break the slot out of the board.

7. Mobile (SODIMM) RAM cannot be installed in the desktop board (with DIMM slots)

At first glance, it seems that this is not a myth - DIMM and SODIMM dies differ in size at times, so laptop RAM simply will not physically fit on a desktop board. But remember about SD cards - they also come in different formats, but with the help of an adapter you can take a microSD and put it in a full-size slot, and it will work without problems.

With RAM, everything is exactly the same: electrically SODIMM from DIMM practically does not differ, so having bought the appropriate adapter, you can easily put laptop RAM into your computer, and it will work without problems. Of course, the question of the advisability of such a solution is open to question, but if you have an extra RAM plate for laptops lying around, and you have nowhere to put it, you can easily upgrade your PC with it.

8. If the processor power connector on the motherboard is 8 pin, then a 4 pin power supply will not work.

It should be understood that the 8 pin power supply on the board is simply 4 + 4 pin (this is hinted at by the fact that many 8 pin power supplies are just represented as 4 + 4), which are connected in parallel:

Accordingly, if you connect only 4 of 8 pins, then the motherboard will work without problems in most cases. Of course, you should understand that you should not seriously load the processor with such a connection - the "extra" 4 pins are just created in order to reduce the heating of the wires from the power supply unit and tracks in the PCB. But if, for example, you bought a new board and CPU, but you didn't have enough money for a new power supply unit with 8 pin, it is quite possible to “sit out” on 4 pin.

9. If the processor is not supported by the motherboard, then nothing can be done, you need to change the board

This is usually not a myth, but in recent times There are enough exceptions: for example, Xeon processors for the server socket LGA771 have become very popular, which on various trading platforms often give away for several hundred rubles. And they, with some desire (cutting the "ears" in a new place and soldering the conductor), can be put into ordinary desktop boards on LGA775:

Another exception is the LGA1151 and 1151v2 sockets: they differ mostly only in software, so with some "magic" with the BIOS, you can make 8th generation processors work on officially unsupported motherboards with 100 or 200 chipsets.

10. Updating the BIOS is a complicated ritual that should not be done on your own

For some reason, for many, the phrase "BIOS update" causes panic and the image of a stern bearded computer technician who plays with floppy disks and prints some incomprehensible characters in command line... Fortunately, for the last 5 years this has not been the case for a long time - BIOS often have friendly user interface in Russian and support working with a mouse, and updating the BIOS is just a couple of mouse clicks, after which the necessary update will be downloaded from the Internet and installed by itself.

There is also an opinion that if everything works, then it is not worth updating the BIOS. Again, this is not the case, because often new BIOS versions have various security fixes (such as patches against Meltdown or Specter), which should not be ignored. And even more so if the board does not work correctly - what happens if you bought it right after the release - often exactly BIOS updates will solve your problems.

11. All slots of the same type on the board are identical, you can use any

Not entirely true: so, usually only the PCIe slot closest to the processor can work on maximum speed x16, the slots below often work only in x8 or x4 mode, so you should not use them with fast video cards:

The same applies to SATA: if you are using an m.2 slot with an NVMe drive at the same time, then one of the SATA connectors may be disabled (since the number of PCIe lanes in the chipset is limited), so do not be surprised that after installing a fast SSD in your computer For some reason, your hard drive has ceased to be detected.

12. Motherboards from XXX are better than YYY

In general, such a comparison is incorrect, just like with other types of equipment. However, there are always brands that produce completely low-quality products: for example, in laptops, these are Digma and iRU. There is a similar division among motherboard manufacturers.

So, MSI, Asus, Gigabyte (as well as Supermicro and Tyan in the server segment) are considered good manufacturers: again, this does not mean that their motherboards are perfect, but still they usually have the least problems. ASRock, Colorful, Biostar, ECS are considered mid-level manufacturers - perhaps it makes sense to compare them with smartphones from Xiaomi: they seem to be cheaper than solutions from AAA brands, but they require some knowledge in order to configure everything as it should, and their BIOS may be raw at first ...

The rest of the motherboards, usually Chinese (from Xuanan) or from OEMs, are often very problematic: they are whimsical to RAM, respond incorrectly to buttons, can turn off during operation, etc. And, alas, there is no need to wait for software fixes - OEMs do not post them on the Internet at all, and you can get them only from new revisions of the board, and Chinese manufacturers usually “forget” about support.

13. Small boards (mATX, mini-ATX) cannot be installed in large cases (Full or Mid Tower)

The myth is again 20 years ago, when compact motherboards had just begun to appear, and the cases simply did not have mounts for them. However, now even the simplest "tin boxes" have such fasteners - another question is why take a spacious case and put a miniature board in it.

14. Boards for processors Intel is better than AMD

The reason for this myth is quite understandable: usually at the start of sales with new AMD processors there are problems: for example, Ryzen was picky about RAM, and not all dies could work at least 3000 MHz. Intel processors are traditionally more stable in this regard, but, in any case, the problem here is software: hardware boards of the same level as for processors from Intel, which for AMD usually differ only in socket and chipset - they are even outwardly extremely similar.

15. For any manipulation with the board, you need to remove the BIOS battery

Do not confuse powering the board (that is, pulling out the power supply cord from the socket) with removing the BIOS battery - the latter is only needed to save BIOS settings if power is suddenly lost. Accordingly, the voltage from it goes only to the BIOS chip, so you can safely assemble the PC completely with the battery inserted. The only exception is if you need to reset the BIOS settings: in this case, it is logical, you need to get the battery.

As you can see, there are many different myths about motherboards. Do you know any more? Write about it in the comments.

Methodology and stand

In today's testing, a large amount of computer hardware was used to show how much power real-life gaming systems consume. In this regard, I relied on assemblies of the "Computer of the month" section. A complete list of all components is shown in the table below.

Test bench, software and auxiliary equipment
CPU	Intel Core i9-9900K Intel Core i7-9700K Intel Core i5-9600K Intel Core i5-9500F AMD Ryzen 5 1600 AMD Ryzen 5 2600X AMD Ryzen 7 2700X
Cooling	NZXT KRAKEN X62
Motherboard	ASUS ROG MAXIMUS XI FORMULA ASUS ROG Crosshair VIII Formula ASUS ROG STRIX B450-I GAMING
RAM	G.Skill Trident Z F4-3200C14D-32GTZ, DDR4-3200, 32 GB Samsung M378A1G43EB-CRC, DDR4-2400, 16 GB
Video card	2 × ASUS ROG Strix GeForce RTX 2080 Ti OC ASUS Radeon VII ASUS DUAL-RTX2070-O8G NVIDIA GeForce RTX 2060 Founders Edition ASUS ROG-STRIX-RX570-4G-GAMING AMD Radeon RX Vega 64 ASUS PH-GTX1660-6G
Storage device	Samsung 970 PRO MZ-V7P1T0BW
Power Supply	Corsair CX450 Corsair CX650 Corsair TX650M Corsair RM850x Corsair AX1000
Frame	Open test bench
Monitor	NEC EA244UHD
Operating system	Windows 10 Pro x64 1903
Software for video cards
NVIDIA	431.60
AMD	19.07.2005
Additional software
Removing drivers	Display Driver Uninstaller 17.0.6.1
FPS measurement	Fraps 3.5.99
	FRAFS Bench Viewer
	Action! 2.8.2
Overclocking and monitoring	GPU-Z 1.19.0
Overclocking and monitoring	MSI Afterburner 4.6.0
Optional equipment
Thermal imager	Fluke Ti400
Sound level meter	Mastech MS6708
Wattmeter	watts up? PRO

Test benches were loaded with the following software:

Prime95 29.8- Small FFT test, which maximizes the load on the central processor. This is a very resource-intensive application, in most cases, programs that use all cores are not able to load the chips more.
AdobePremierPro 2019- rendering of 4K video by means of the central processor. An example of resource-intensive software that uses all processor cores, as well as available reserves of RAM and storage.
"The Witcher 3: Wild Hunt"- testing was carried out in full screen mode in 4K resolution using maximum graphics quality settings. This game puts a heavy load on not only the video card (even two RTX 2080 Ti in the SLI array are 95% loaded), but also the central processor. Eventually system unit loads more than, for example, using FurMark "synthetics".
"The Witcher 3: Wild Hunt" +Prime95 29.8(Small FFT test) - a test for the maximum power consumption of the system when both the CPU and GPU are loaded at 100%. And yet, it should not be ruled out that there are more resource-intensive bundles.

Energy consumption was measured using a watts up? PRO - despite such a comical name, the device can be connected to a computer, and with the help of special software it allows you to monitor its various parameters. So, the graphs below will show the average and maximum power consumption levels of the entire system.

The period of each power measurement was 10 minutes.

⇡ What power is needed for a modern gaming PC

I will note again: this article is to a certain extent tied to the "Computer of the Month" section. Therefore, if you have dropped by to see us for the first time, then I recommend that you familiarize yourself with at least. In each "Computer of the Month" six assemblies are considered - mostly games. I have used similar systems for this article. Let's get acquainted:

A bundle of Ryzen 5 1600 + Radeon RX 570 + 16 GB of RAM is an analogue of the starting assembly (35,000-37,000 rubles per system unit, excluding the cost of software).
Bundle Ryzen 5 2600X + GeForce GTX 1660 + 16 GB of RAM is an analogue of the base assembly (50,000-55,000 rubles).
A bundle of Core i5-9500F + GeForce RTX 2060 + 16 GB of RAM is an analogue of the optimal assembly (70,000-75,000 rubles).
A bundle of Core i5-9600K + GeForce RTX 2060 + 16 GB of RAM is another option for the optimal assembly.
A bundle of Ryzen 7 2700X + GeForce RTX 2070 + 16 GB of RAM is an analogue of an advanced assembly (100,000 rubles).
A bundle of Ryzen 7 2700X + Radeon VII + 32 GB of RAM is an analogue of the maximum assembly (130,000-140,000 rubles).
A bundle of Core i7-9700K + Radeon VII + 32 GB of RAM is another option for the maximum build.
A bundle of Core i9-9900K + GeForce RTX 2080 Ti + 32 GB of RAM is an analogue of an extreme assembly (220,000-235,000 rubles).

Unfortunately, I could not get the Ryzen 3000 processors at the time of all the tests, but the results obtained from this will not become less useful. The same Ryzen 9 3900X, consumes less Core i9-9900K - it turns out that within the framework of an extreme assembly, it will be even more interesting and important to study the power consumption of an 8-core Intel.

And also, as you may have noticed, the article uses only mainstream platforms, namely AMD AM4 and Intel LGA1151-v2. I didn't use HEDT systems like TR4 and LGA2066. First, we have long since abandoned them in Computer of the Month. Secondly, with the appearance in the mass segment of the 12-core Ryzen 9 3900X and in anticipation of the imminent release of the 16-core Ryzen 9 3950X, such systems have become painfully highly specialized. Thirdly, because the Core i9-9900K still gives everyone a light in terms of energy consumption, once again proving that the calculated thermal power declared by the manufacturer says little to the consumer.

Now let's move on to the test results.

To be honest, the test results in programs such as Prime95 and Adobe Premier Pro 2019, I cite more for your information - for those who do not play and do not use discrete graphics cards. You can safely focus on this data. Basically, here we are interested in the behavior of test systems in loads close to maximum.

And here are very interesting things. In general, we see that all considered systems do not consume very much energy. The most gluttonous, which is quite logical, was the system with Core i9-9900K and GeForce RTX 2080 Ti, but even in stock (read - without overclocking) consumes 338 W when it comes to games, and 468 W - at maximum PC load. It turns out that such a system will have enough power supply for an honest 500 watts. It is so?

⇡ It's not just about watts

It would seem that this is the end of the article: recommend everyone a power supply with a capacity of 500 honest watts - and live in peace. However, let's do some additional experimentation to get a complete picture of what's going on with your PC.

In the screenshot above, we see that the power supplies work as efficiently as possible at 50% load, that is, half of the declared power. It may seem to some that the difference between a device with a basic 80 PLUS certification with an efficiency at the peak of about 85% in a 230 V network and, say, a "platinum" PSU with an efficiency of about 94% is not so great, but this is a delusion. my colleague Dmitry Vasiliev points out quite accurately: “A source of energy with an efficiency of 85% uselessly spends 15% of its power on heating the ambient air, and with an efficiency of 94%, only 6% of the power is converted into heat by the“ breadwinner ”. It turns out that the difference is not “ some there"10%, but x2.5". Obviously, in such conditions, a more efficient power supply unit runs quieter (it makes no sense for the manufacturer to adjust the fan of the device to the maximum rotational speed), and it heats up less.

And here is the proof of the above words.

The graphs above show the efficiency of some power supplies participating in the tests, as well as the rotational speed of their fans at different degrees of load. Unfortunately, the equipment used does not allow us to accurately measure the noise level, but by the number of revolutions per minute of the built-in fans, we can judge how noisy the power supply will be. It should be noted here that this does not mean at all that under load the PSU will stand out “from the crowd”. Still, usually the noisiest components of a gaming computer are the CPU cooler and graphics card.

Practice, as you can see, converges with theory. The power supplies do operate at their maximum efficiency at about 50 percent load. Moreover, in this regard, I would like to note the Corsair AX1000 model - this power supply reaches its peak efficiency with a power of 300 W, and then its efficiency does not fall below 92%. But other Corsair blocks on the charts have the expected "hump".

At the same time, the Corsair AX1000 can operate in a semi-passive mode. Only at a load of 400 W does its fan start spinning at a frequency of ~ 750 rpm. The RM850x has the same characteristic, but in it the impeller starts to rotate at a power of ~ 200 W.

Now let's take a look at the temperatures. To do this, I disassembled all the power supplies. The fans from the top cover were removed and installed on a homemade tripod so that the distance between it and the rest of the PSU was about 10 cm. I'm sure the device did not work worse in terms of cooling, but this design allowed me to take pictures with a thermal imager. In the graph above, "Temperature 1" refers to the maximum temperature of the power supply inside when the fan is running. "Temperature 2" is the maximum heating of the PSU ... without additional cooling. Please do not repeat such experiments at home on your equipment! However, such a bold move allows you to clearly show how the power supply heats up and how its temperature depends on the rated power, build quality and the component base used.

Heating the CX450 to 117 degrees Celsius is quite a logical phenomenon, because this power supply operates at a load of 400 W at almost maximum, and even does not cool down in any way. The fact that the power supply has passed this test at all is an excellent sign. Here is a high quality budget model.

Comparing the results of other power supplies, we can come to the conclusion that they seem quite logical: yes, the Corsair CX450 model heats the most, and the RM850x least of all. At the same time, the difference in the maximum heating rates is 42 degrees Celsius.

It is important here to define the concept of “honest power”. Here is the Corsair CX450 model on the 12-volt line can transfer 449 watts of power. It is this parameter that must be looked at when choosing a device, because there are models that do not work as efficiently. In cheaper units of similar power, noticeably fewer watts can be transmitted over a 12-volt line. It comes to the point that the manufacturer claims support for 450 watts, but in fact it is only about 320-360 watts. So let's write down: when choosing a power supply, you need to look, among other things, at how many watts the device produces over a 12-volt line.

Let's compare the Corsair TX650M and CX650, which have the same power rating but are certified to different 80PLUS gold and bronze standards, respectively. I think the images of the thermal imager attached above speak more eloquently than any words. Really, support for a specific standard 80PLUS indirectly speaks about the quality of the element base of the power supply... The higher the certificate class, the better the power supply.

It is important to note here that the Corsair TX650M transmits up to 612 watts over the 12-volt line, and the CX650 up to 648 watts.

Above in the pictures you can compare the heating of the RM850x and AX1000 models, but already at a load of 600 watts. Here, too, there is an obvious difference in temperatures. Overall, we can see that Corsair PSUs do a good job of handling their assigned load - and in stressful situations, too. At the same time, I think it is now clear why the graph above did not show the temperature of the AX1000 - it does not heat up much, even if the cover with the fan is removed from it.

Considering the results obtained, you can see that it is completely unreasonable to use a power supply in the system with a power twice the maximum power of the PC itself. In this operating mode, the power supply unit heats up less and makes noise - these are facts that we have just proved once again. It turns out that a power supply unit with an honest power of 450 W is suitable for a starting assembly, for a basic one - 500 W, for an optimal one - 500 W, for an advanced one - 600 W, for a maximum one - 800 W, and for an extreme one - 1000 W. Plus, in the first part of the article, we found out that there is not such a big difference in price between power supplies, the declared power of which differs by 100-200 watts.

However, let's not rush to final conclusions.

⇡ A few words about the upgrade

The assemblies in "Computer of the Month" are designed not only to work in the default mode. In each issue, I talk about the overclocking capabilities of some components (or the pointlessness of overclocking in the case of some processors, memory and video cards), as well as the possibilities of the subsequent upgrade. There is an axiom: the cheaper the system unit, the more compromises it has... Compromises that will allow you to use a PC here and now, but the desire to get something more productive, quiet, efficient, beautiful or comfortable (necessary - emphasize) will not leave you anyway. Captain Evidence suggests that in such situations, a power supply unit with a good watt margin will be very useful.

Let me give you an illustrative example of upgrading the starting assembly.

I took the AM4 platform. recommended 6-core Ryzen 5 1600, Radeon RX 570 and 16GB DDR4-3000 RAM. Even with a stock cooler (a cooling system that comes with the CPU), our chip can be easily overclocked to 3.8 GHz. Let's say I took a radical step and changed the CO for a much more efficient model, which allowed me to raise the frequency from 3.3 to 4.0 GHz while loading all six cores. To do this, I needed to raise the voltage to 1.39 V, and also set the fourth level of Load-Line Calibration of the motherboard. This overclocking essentially turned my Ryzen 5 1600 into a Ryzen 5 2600X.

Let's say I bought Radeon graphics RX Vega 64 - on the Computeruniverse website a month ago it could be taken for 17,000 rubles (excluding delivery), and even cheaper from hands. And in the comments to "Computer of the Month" they talk so sweetly about the used GeForce GTX 1080 Ti, sold for 25-30 thousand rubles ...

Finally, instead of the Ryzen 5 1600, you can take the Ryzen 2700X, which has significantly dropped in price after the release of the third-generation AMD family of chips. There is no particular need to disperse it. As a result, we see that in both cases of the upgrade I proposed, the power consumption of the system has more than doubled!

This is just an example, and the actors in the described situation may be completely different. However, this example, in my opinion, clearly shows that even in the starting assembly, a power supply with an honest power of 500 W, or even better 600 W, does not interfere at all.

⇡ Overclocking and everything connected with it

Speaking of overclocking, I will give an example of the power consumption of the stands before and after overclocking. The frequencies have been increased for the following systems:

Ryzen 5 1600 (@ 4.0 GHz, 1.39 V, LLC 4) + Radeon RX 570 (1457/2000 MHz) + 16GB RAM (DDR4-3200, 1.35 V).
Ryzen 5 2600X (@ 4.3 GHz, 1.4 V, LLC 4) + GeForce GTX 1660 (1670/2375 MHz) + 16 GB RAM (DDR4-3200, 1.35 V).
Core i5-9600K (@ 4.8 / 5.0 GHz, 1.3 V, LLC 4) + GeForce RTX 2060 (1530/2000 MHz) + 16 GB RAM (DDR4-3200, 1.35 V).
Ryzen 7 2700X (@ 4.3 GHz, 1.4 V, LLC 4) + GeForce RTX 2070 (1500/2000 MHz) + 16 GB RAM (DDR4-3200, 1.35 V).
Ryzen 7 2700X (@ 4.3 GHz, 1.4V, LLC 4) + Radeon VII (2000/1200 MHz) + 32GB RAM (DDR4-3400, 1.4V).
Core i7-9700K (@ 5.0 / 5.2 GHz, 1.35 V, LLC 5) + Radeon VII (2000/1200 MHz) + 32 GB RAM (DDR4-3400, 1.4 V).
Core i9-9900K (@ 5.0 / 5.2 GHz, 1.345 V, LLC 5) + GeForce RTX 2080 Ti (1470/1980 MHz) + 32 GB RAM (DDR4-3400, 1.4 V).

"Gaming PCs do not need 1 kW units" - commentators under the articles on the site

Such comments are often seen when it comes to gaming PCs. In the vast majority of cases - and we found it out in practice - this is how it is. However, in 2019 there is a system that is able to impress with its power consumption.

We are talking, of course, about an extreme assembly in its, so to speak, maximum combat form. Not so long ago, an article "" was published on our site - in it we talked in detail about the performance of a pair of the fastest GeForce video cards in 4K and 8K resolutions. The system is fast, but the components are selected in such a way that it is very easy to make it even faster. In addition, it turned out that overclocking the Core i9-9900K to 5.2 GHz turns out to be completely useful in the case of the GeForce RTX 2080 Ti SLI array and Ultra HD games. Only at its peak, as we can see, such an overclocked configuration consumes more than 800 watts. Therefore, for such a system in such conditions, a kilowatt power supply will definitely not be superfluous.

⇡ Conclusions

If you have carefully read the article, then you have identified for yourself several main points that you need to keep in mind when choosing a power supply. Let's list them all again:

unfortunately, it is impossible to focus on the TDP indicators declared by the manufacturer of the video card or processor;
the power consumption of computer equipment does not change much from year to year and is within certain limits - therefore, a high-quality power supply purchased now will last a long time and faithfully and will definitely come in handy during the assembly of the next system;
the needs for cable management of the system unit also affect the choice of a power supply unit of a certain power;
not all power connectors on the motherboard need to be used;
the power supply unit of lower power is not always more profitable (in terms of price) than a more powerful model;
when choosing a power supply, one must look at how many watts the device gives out on a 12-volt line;
support for a certain standard 80 PLUS indirectly speaks of the quality of the element base of the power supply;
it is completely unjustifiable to use a power supply whose honest power is twice (or even more) the maximum power consumption of the computer.

Quite often you can hear the phrase: “ More is not less". This very laconic aphorism perfectly describes the situation when choosing a power supply. Take a model with a good power reserve for your new PC - it will definitely not get worse, but in most cases it will only get better. Even for an inexpensive gaming system unit, which consumes about 220-250 W at maximum load, it still makes sense to take a good model with an honest 600-650 W. Because a block like this:

will work quieter, and in the case of some models - absolutely silent;
it will be colder;
will be more efficient;
will allow you to easily overclock the system, increasing the performance of the central processor, video card and RAM;
will allow you to easily upgrade the main components of the system;
will survive several upgrades, and also (if the power supply is really good) will settle in the second or third system unit;
will also allow you to save money during the subsequent assembly of the system unit.

I think very few readers will refuse a good power supply. It is clear that it is not always possible to immediately buy a high-quality device with a large reserve for the future. Sometimes, when buying a new system unit and a limited budget, you want to take a more powerful processor, and faster video cards, and a higher-capacity SSD - all this is understandable. But if you have the opportunity to buy a good power supply with a margin, you don't need to save on it.

We express our gratitude to the companiesASUS andCorsair, as well as the computer store "Regard" for the equipment provided for testing.

CPU power connectors

The CPU is powered by a device called the Voltage Regulator Module (VRM), which is found in most motherboards. This device provides power to the processor (typically through pins on the processor socket) and self-calibrates to supply the correct voltage to the processor. The VRM is designed to be powered by both +5 V and +12 V input.

For many years, only +5 V was used, but since 2000, most VRMs have switched to +12 V due to lower requirements for handling this input voltage. In addition, other PC components can also use the +5 V voltage supplied through the common pin on the motherboard socket, while only disk drives are "hung" on the +12 V line (at least, this was the case before 2000).

Whether the VRM on your board uses + 5V or + 12V depends on specific model boards and designs of the voltage regulator. Many modern VRMs are designed to accept input voltages from +4 V to +26 V, so the final configuration is determined by the motherboard manufacturer.

For example, somehow we got a FIC (First International Computer) SD-11 motherboard equipped with a Semtech SC1144ABCSW voltage regulator.

This board uses +5 V, converting it to a lower voltage according to the needs of the CPU. Most motherboards use VRMs from two manufacturers - Semtech or Linear Technology. You can visit the websites of these companies and study the specifications of their chips in more detail.

The motherboard in question used an Athlon 1 GHz Model 2 processor with a slotted slot (Slot A) and was specced to require 65W at 1.8V nominal. 65W at 1.8V corresponds to 36 , A.

When using a VRM with an input voltage of +5 V and a power of 65 W, the current strength is only 13 A. But this arrangement is obtained only if the voltage regulator is 100% efficient, which is impossible. Usually, the VRM efficiency is about 80%, so the current should be approximately equal to 16.25 A.

When you consider that other power consumers on the motherboard also use the +5 V line - remember that ISA or PCI cards also use this voltage - you can see how easy it is to overload the +5 V lines on the PSU.

Although most VRM designs on motherboards are inherited from Pentium III and Athlon / Duron processors that use +5 V regulators, most modern systems use VRMs designed for a voltage of +12 V. This is due to the fact that more high voltages reduce the current level. We can verify this with the example AMD Athlon 1 GHz already mentioned above:

As you can see, using the + 12V line to power the chip requires a current of only 5.4 A or 6.8 A, taking into account the efficiency of the VRM.

So we could get a lot of value by connecting the VRM on the motherboard to the + 12V power line. But, as you already know, the ATX 2.03 specification assumes only one + 12V line, which is sent through the main power cable of the motherboard.

Even the short-lived auxiliary 6-pin connector was devoid of contact with the + 12V voltage, so it could not help us. A current greater than 8 A on a single 18 gauge wire from the +12 V line to the PSU is very efficient way melt the pins of the ATX connector, which, according to the specification, are designed for a current not exceeding 6 A when using standard Molex pins. Thus, a fundamentally different solution was required.

Platform Compatibility Guide (PCG)

The processor directly controls the current through the + 12V pin. Modern motherboards are designed to support as many processors as possible, however, some motherboards' VRM circuits may not provide enough power for all processors that may be installed in a socket. on the motherboard.

To eliminate potential compatibility issues that can lead to unstable PC operation or even failure of individual components, Intel developed a power standard called the Platform Compatibility Guide (PCG).

PCG is mentioned on most of the box Intel processors and motherboards from 2004 to 2009. It was created for PC builders and system integrators to inform them about the power requirements of the processor, and whether the motherboard meets these requirements.

PCG is a two-digit or three-digit designation (for example, 05A), where the first two digits represent the year the product was introduced, and an additional third letter corresponds to the market segment.

PCG markings, including the third character A, correspond to low-end processors and motherboards (require less power), while the letter B refers to processors and motherboards related to the high-end market segment (require more power ).

Motherboards that support high-end processors, by default, can also work with less powerful processors, but not vice versa.

For example, you can install a 05A-marked PCG processor into a 05B-marked motherboard, but if you try to install a 05B processor into a 05A-marked PCG, you may well face system instability or other, more serious consequences.

In other words, it is always possible to install a less efficient processor in an expensive motherboard, but not vice versa.

4-pin + 12V processor power connector

To increase the current on the + 12V line, Intel created a new ATX12V PSU specification. This led to a third power connector called ATX + 12V and was used to supply an additional + 12V voltage to the motherboard.

This 4-pin power connector is standard on all ATX12V motherboards and contains Molex Mini-Fit Jr. pins. with female plugs. According to the specification, the connector complies with the Molex 39-01-2040 standard, the connector type is Molex 5556. This is the same type of pins used in the main power connector of the ATX motherboard.

This connector has two +12 V contacts, each of which is rated for a current of up to 8 A (or up to 11 A when using HCS contacts). This provides a current of 16 A in addition to the contact on the motherboard, and in total both connectors provide a current of up to 22 A on the +12 V line. The pin assignment of this connector is shown in following scheme:

Using standard Molex contacts, each pin in the + 12V connector can conduct up to 8A, 11A with HCS contacts, or 12A with Plus HCS contacts. Even though this connector uses the same pins as the main one, the current through this connector can reach more than high values as fewer contacts are used. By multiplying the number of contacts by the voltage, you can determine the maximum current power for a given connector:

Molex standard contacts are rated for 8 A.

Molex HCS contacts are rated for 11 A.

Molex Plus HCS contacts are rated for 12 A.

All values are for a Mini-Fit Jr. 4-6 pin bundle. using 18 gauge wires and standard temperature.

Thus, in the case of using standard contacts, the power can reach 192 W, which, in most cases, is sufficient even for modern high-performance CPUs. Consumption of more power can lead to overheating and melting of the contacts, therefore, in the case of using more "gluttonous" processor models, the + 12V plug to power the processor must include the Molex HCS or Plus HCS contacts.

The 20-pin main power connector and the + 12V processor power connector together provide a maximum current of 443W (using standard pins). It is important to note that the addition of a + 12V connector allows the full power of the 500W PSU to be used without the risk of overheating or melting the contacts.

Adapter for +12 V processor power connector

If the power supply does not have a standard + 12V connector for powering the processor, and the motherboard has a corresponding socket, there is a simple way out of the problem - use an adapter. What nuances can we face in this case?

The adapter connects to the connector for peripheral devices, which is available in almost all power supplies. The problem is in this case is that the connector for peripheral devices has only one + 12V contact, and the 4-pin CPU power connector has two such contacts.

Thus, if the adapter assumes the use of only one connector for peripheral devices, using it to provide voltage on two pins of the +12 V connector for the processor at once, then in this case we see a serious discrepancy between the current requirements.

Since the pins on the peripheral connector are rated for only 11 amps, a load exceeding this value could overheat and melt the pins on that connector. But 11 A is below the current peak values that the connector pins should be rated for in accordance with the Intel PCG recommendations. This means that these adapters do not comply with the latest standards.

We made the following calculations: given a VRM efficiency of 80%, for an average processor consuming 105W, the current level will be approximately 11A, which is the maximum for the peripheral power connector.

Many modern processors have a TDP in excess of 105W. But we would not recommend using adapters that use only one connector for peripheral devices with processors with a TDP over 75W. An example of such an adapter is shown in the following figure:

8-pin +12 V processor power connector

High-end motherboards often use multiple VRMs to power the processor. To distribute the load between additional voltage regulators, these boards are equipped with two 4-pin + 12V connectors, but they are physically combined into one 8-pin connector, as shown in the figure below.

This type of connector was first introduced in the EPS12V specification version 1.6, released in 2000. Although this specification was originally focused on file servers, the increased power demands of some high-end desktop processors have led to this 8-pin connector appearing in the PC world.

Some motherboards that use an 8-pin CPU power connector must receive voltage across all pins of the connector to work correctly, while most motherboards of this type can work even if you only use one 4-pin power connector. In the latter case, there will be four free contacts on the motherboard socket.

But before starting a computer with such a configuration of connectors, you need to read the motherboard user manual - most likely, it will reflect whether it is possible to connect one 4-pin power connector to an 8-pin socket on the board, or not.

If you are using a processor that draws more power than a single 4-pin power connector can supply, you will still need to find a PSU equipped with an 8-pin connector.

Adapter 4-pin -> 8-pin CPU + 12V power connector

If the motherboard requires voltage on all eight pins, but at the same time you are using a not too "gluttonous" processor and your power supply does not have an 8-pin connector, then an adapter from a 4-pin to an 8-pin connector can come to the rescue. It looks like this:

There are adapters that work in the opposite direction - that is, they convert the signal from an 8-pin connector to a 4-pin one.

But they are rarely required, as you can do it easier by plugging the 8-pin connector into the four sockets on the motherboard.

To do this, you just need to move the connector to one side. An adapter is indispensable if the physical layout of the board does not allow for an offset 8-pin connector.

#Lines_number_ + 12V

You can independently identify how many lines in a particular power supply unit can be by its label - if there are more than one lines, then the maximum load in amperes is separately indicated for each + 12V circuit, which are designated as "+ 12V1, + 12V2, etc.". The actual output lines in English are called "rails", and, accordingly, a power supply unit with one output line will be called "single rail PSU", and with several - "multiple rails PSU".

PSU with one line + 12V

PSU with multiple lines + 12V

There are several models of power supplies that actually have two voltage sources + 12V, but these are usually very high power supplies (from 1000W). And in most cases, these two exits are again divided into four, five or six lines for security reasons. (But, for example, u do not share, and this is not so bad, which will be discussed later)

In some even rarer cases, the two original + 12V lines can be combined into one powerful output.

So why do you really need to separate the + 12V lines?

Security. For the same reason, houses, as a rule, have more than one fuse-switch (popularly known as "packet bags"). The ultimate goal is to limit the current in one circuit to 20A so that the temperature of the conductor carrying it does not become dangerous.

Short-circuit protection is triggered only when there is almost complete absence of resistance in the short-circuited circuit (that is, for example, when a bare wire hits "ground"), and in more difficult cases, when a short circuit occurs on a printed circuit board or in an electric motor, the resistance in the circuit remains sufficient to prevent short-circuit protection from tripping. In this case, a very large load on the circuit arises and a rapid increase in the current strength in the conductors leads, first of all, to the melting of the insulation and subsequently to a fire. Limiting the current on each line removes this problem, i.e. that is why it is necessary to divide the outputs into separate lines with individual stops.

Is it true that in some power supplies with the declared multiple + 12V lines, there is no line separation at all?

Yes it is. Fortunately, this is the exception to the rule, not the norm. This is done to reduce development and production costs. Why is it stated that there are several lines - in order to fully comply with the ATX12V specification, because in other characteristics it is observed.

Why do such power supplies remain on the market, and manufacturers have no problems with their certification?

Yes, because Intel recently removed the + 12V line splitting requirement from the specification, but has not publicly announced this fact. They just changed "required" to "recommended", leaving the manufacturers a little puzzled.

Does splitting the + 12V lines give "cleaner and more stable voltages"?

The truth is that marketers constantly emphasize this fact, but usually it is not, it just sounds more euphonious than "This PSU is unlikely to cause a fire." And since, as already mentioned above, all lines in most cases originate from one source, and no additional filtering is performed, the voltages remain the same even if there were no divisions.

Why do some people presume that a PSU with a single + 12V output is better?(just a great example -)

There were a few companies that made PSUs with four 12V lines that, in theory, were supposed to supply more than enough current for a high-end gaming station and ran into a lot of problems. Making the PSU in accordance with the EPS12V server specification, all PCI-E 6-pin connectors were removed from the common + 12V lines with a load capacity of 18A, instead of a separate one. This line was easily overloaded with two powerful graphics cards along with other possible consumers, resulting in a PC shutdown. Instead of a "civilized" solution to the problem, these manufacturers have given up on dividing + 12V outputs altogether.

Now power supply units "for enthusiasts" with several + 12V lines have either an overestimated maximum load capacity of the line intended for PCI-E connectors (and nothing else is connected to it), or two such lines are distributed over four or even six connectors. And PS certification for SLI in any case requires at least a separate + 12V line for PCI-E connectors.

To make a PSU with split lines costs $ 1.5-3 more for the manufacturer, and in most cases this amount is not passed on to the buyer, which already forces marketers to put forward theories that PSUs with + 12V lines without splitting are no worse or even better. ...

But nevertheless, there are statements that, for example, power supplies with one + 12V line are better suited for overclocking, etc. But this is more like a placebo effect, which arose due to the fact that, for example, their previous PSU was faulty, was not powerful enough, or the load was not properly distributed along the lines.

So it turns out that a power supply unit with + 12V load distribution over several lines does not have any specific drawbacks?

No, actually, it is not. Let's look at two examples:

Example # 1:

One power supply model with a nominal value of 700W formally has enough power for any SLI system of two single-chip video cards. But this PSU has only two PCI-E connectors, each of which hangs on its own + 12V line. The problem is that these lines are capable of delivering 18 amps, which is almost three times the maximum current that the 6-pin PCI-E graphics card connector can handle. Accordingly, when you try to install two video cards that require two of these connectors, problems begin.

It would be ideal if two connectors were soldered to each of the lines, but instead you have to use adapters from the "regular" 4-pin Molex to PCI-E 6-pin, which leads to an overload of the circuits from which the rest of the system is powered. block, while the actual "video card" circuits remain heavily underloaded. The problem could be solved by a 6-pin PCI-E -> 2x 6-pin PCI-E adapter in two copies, but it cannot be called widespread. So in such a situation, the best solution to the problem (in addition to replacing the power supply unit) is to independently solder two PCI-E connectors to two corresponding lines.

Example # 2:

Thermo-electric coolers (also called Peltier coolers) consume a lot of power and are usually powered by Molex connectors. Some models generally use their own separate power supply unit.

So, if you use a power supply unit with line separation and powered your Peltier element from one of the molecules, then it turns out to be on the same line with accumulators, fans, etc., then this line may also be overloaded, since it is transplanted to other lines, designed to power video cards is impossible without significant tweaks. Naturally, a power supply unit with one + 12V line would be devoid of any problems in such a situation.

Typical configurations for multiple + 12V lines:

2 x 12V lines, example -
This is the original ATX12V specification for dividing + 12V lines. One is for the processor, the other is for everything else. It is very unlikely that a modern high-end graphics card with high power consumption will fit into the "everything else". Such a division could only be seen on a power supply unit with a power less than 600W.
3 x 12V lines, example -
Modifications to the ATX12V specification, taking into account the use of PCI-E connectors for powering video cards. One lane per processor, one lane for PCI-E connectors, and one lane for everything else. Works great even with some SLI configurations, but not recommended for two video cards that require four PCI-E connectors in total.
4 x 12V lines (EPS12V), example -
In the original, this configuration was required by the EPS12V specification. Since typical applications of such PSUs imply their use in dual-processor systems, the two + 12V lines are intended exclusively for powering the processors via 8-pin connectors. Everything else, including drives and video cards, falls on the two remaining lines. Currently, nVidia does not certify such power supplies for SLI, since there is no separate + 12V line for video cards in such power supplies. In the segment of PSUs that are not intended for servers, there will no longer be such PSUs; several 700-850W models made according to such an architecture for the gaming PC market have already been discontinued.
4 x 12V lines (The most popular layout in the "PC for enthusiasts" segment), example -
"Upgraded" ATX12V, similar to 3 x 12V, apart from the fact that two to six PCI-E connectors are split between two additional + 12V lines. Such a scheme is most often found in a power supply unit with a power from 700 to 1000 watts, although at a power of 800 watts or more, some of the lines may have much more than 20 amperes, which is not quite standard, but it seems to have already become a common practice, for example -
5 x 12V lines, for example -
Such power supplies can be called a hybrid EPS12V / ATX12V. Two processors with their own power lines, also two lines go to PCI-E connectors. The power of such PSUs usually ranges from 850 to 1000 watts.
6 x 12V lines, example -
The most attractive and versatile option, since, in accordance with the EPS12V specification, it can have four to six PCI-E connectors without exceeding the current of 20A on any of the lines (although in practice this limitation, as you have already seen, is interpreted rather loosely). Two lines go to processors, two to video cards, two to everything else. This configuration can be seen in a power supply unit with a capacity of 1000 watts or more.

As a conclusion, we can note the fact that 99% of users will never think about whether their power supply has a common or separate + 12V lines. Perhaps marketers will continue to extol the merits of both options, but the criteria for buying a PSU will still remain the same:

Sufficient power for the selected configuration.
Sufficient number of suitable connectors for the selected configuration.
SLI or CrossFire certified when using the appropriate MultiGPU configuration.

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