8 pin connector. Pinout of computer power supply connectors. Adapter from connector for peripheral devices to SATA
Standard power supplies operate from 220V, and may also have a mechanical input voltage switch of 110V or 220V AC (alternating current). The computer power supply is designed to convert alternating voltage 220 volts DC into direct current +12 volts, +5 volts, +3.3 volts, then the direct current is used to power the computer components. 3.3 and 5 volts are commonly used in digital circuits, while 12 volts is used to run drive motors and fans.
ATX 20 and 24 Pin main power cable connector
The 24-pin 12-volt ATX power connector can only be plugged in one direction into the motherboard slot. If you look closely at the image at the top of this page, you will see that the pins have a unique shape that only corresponds to one direction on the motherboard. The original ATX standard supported a 20-pin connector with a very similar pinout to the 24-pin connector, but skipped pins 11, 12, 23, and 24. This means that the newer 24-pin power supply is useful for motherboards that require more power. Modern motherboards may have only 2 types of connectors: a 20-pin main power connector or a 24-pin main power connector.
Many power supplies come with 20+4 pin chips, which is compatible with 20 and 24 pin motherboard power slots. In 20+4, the power cable consists of two parts: a 20-pin and a 4-pin chip. If you disconnect the two parts separately then you can connect the 20 pin connector and if you connect the two 20+4 power cable chips together then you will get a 24 pin power cable which can be connected to the 24 pin power slot of the motherboard .
ATX 4-Pin Power Connector
Molex 4-Pin Peripheral Connector Power Cable
Four-pin peripheral power cable. It was used for floppy disks and hard drives and is still very widely used today. You don't have to worry about installing this connector; it cannot be installed incorrectly. People often use the term "4-pin Molex power cable" or "4-pin Molex" to refer.
SATA 15-Contact to power cable
SATA was introduced to upgrade the ATA (also called IDE) interface to a more advanced design. The SATA interface includes both a data cable and a power cable. The power cable replaces the old 4-pin peripheral cable and adds support for 3.3 volts (if fully implemented).
8-Pin EPS and +12 Volt Power Connector
This cable was originally created for workstations to provide 12 volts of multiple power. But since a lot of time has passed, processors require more power and an 8-pin cable is often used instead of a 4-pin 12 volt cable. It is often called "EPS12V" cable.
4+4 Pin EPS +12 Volt Power Connector
Motherboards can be with a 4-pin connector or an 8-pin 12 volt connector. Many power supplies are equipped with a 4+4 pin 12 volt cable that is compatible with 4 and 8 pin mains. A 4+4 power cable has two separate 4 pins. If you connect them together, a 4+4 power cable, then you will have an 8-pin power cable that can be connected to an 8-pin connector. If you leave the two parts separately, then you can connect one of the plugs to the 4-pin motherboard connector.
6-pin PCI Express (PCIe) power cable Connector
This cable is used to provide an additional 12 volts of power for the PCI Express expansion card. This connector can provide up to 75W of PCI Express power.
8-pin PCI Express (PCIe) power cable connector
PCI Express specification version 2.0 released in January 2007 added an 8-pin PCI Express power cable. This is simply an 8-pin version of the 6-pin PCI Express with a power cable. Both are used primarily to provide additional power to the graphics card. The older 6-pin version officially delivers no more than 75W (although unofficially it can typically deliver significantly more), while the newer 8-pin version delivers a maximum of 150W.
6+2(8) pin PCI Express (PCIe) power cable connector
Some video cards have 6-pin PCI Express power connectors and others have 8-pin PCI Express connectors. Many power supplies come with a 6+2 PCI Express power cable that is compatible with both types of graphics cards. In 6+2 PCI Express, the power cable consists of two parts: 6-pin and 2-pin. If you put these two parts together, you have a full 8-pin PCI-Express connector. But if you split the connector into two parts, then you can only connect the 6-pin one.
Except for the motherboard connectors, everything Power supplies are also equipped with various additional connectors, most of which are designed to power disk drives and other peripheral devices, such as a powerful video card. Most peripheral connectors, in turn, comply with industry standards for a particular form factor. In this part of our material we will look at what additional connectors you can find in your PC.
Peripheral power connector
Perhaps the most common type of connector that can be found on all power supplies is the peripheral power connector, which is also often called the disk drive power connector. What we understand as this type of connector first appeared in the AMP power supplies in the PSU series and was called the MATE-N-LOK connector, but since it began to be manufactured and sold by Molex, it has also been called the “Molex connector” which is not entirely correct.
To determine the pin location, look closely at the connector. As a rule, on the right side of the plug there is a plastic tab and a key, which is necessary for correctly fixing the connector in the socket. The following diagram shows a standard connector with a key on the plug. This is the connector that is used to power disk drives (and not only):
Peripheral power connector
This connector has been used on all PCs, from the original IBM PC to modern systems. It is best known as a disk drive connector, but is also used in some systems to provide additional power to the motherboard, graphics card, cooling fans, and any other PC components that may use +5 V or +12 V.
This is a 4-pin connector that has four round-shaped contacts located at a distance of 5 mm from each other and rated for a current of up to 11 A each. Since the connector includes one +12 V and one +5 V contact (the other two are ground), the maximum current power through the connector reaches 187 W. The connector plug is about 2 cm wide and can be connected to most disk drives and some other PC components. In the following table we show the assignment of contacts on this connector:
| Contacts on the power connector for peripheral devices | |||||
| Contact | Signal | Color | Contact | Signal | Color |
| 1 | +12 V | Yellow | 3 | Gnd | Black |
| 2 | Gnd | Black | 4 | +5 V | Red |
Floppy drive power connector
In the mid-1980s, 3.5-inch magnetic disk drives first appeared, and then it became clear that they needed a more compact power connector. The answer was what is today known as the floppy drive power connector, which was developed by AMP as part of the EI (Economy Interconnection) series. These connectors are used to power small disk drives and devices, and have the same +12 V, +5 V and ground pins as the large peripheral connector. The distance between the contacts in this type of plug is 2.5 mm, and the plug itself is about half the size of a large connector. All contacts are rated at 2 A each, so the maximum current through this connector is only 34 W.
The following table shows the pin configuration on the floppy drive power connector:
| Contacts on the floppy drive power connector | |||||
| Contact | Signal | Color | Contact | Signal | Color |
| 1 | +5 V | Red | 3 | Gnd | Black |
| 2 | Gnd | Black | 4 | +12 V | Yellow |
The power connector for peripheral devices and its younger brother have a universal pin layout, as can be seen in the following diagram:
Peripheral power connector and floppy drive connector
The pin layout of the floppy connector is mirrored compared to the larger peripheral connector. When using an adapter from one type of connector to another, you should be careful and remember that in this case the red and yellow wires are swapped.
First Power supplies were equipped with only two connectors for peripherals, while modern power supplies have four or more large connectors and one or two connectors for floppy drives. Depending on the power and purpose, some power supplies have eight or even more connectors for peripheral devices.
If you use many hard drives or other devices that require additional power, you can use a Y-splitter, as well as a large-to-small connector adapter. The splitter allows you to turn one power connector for peripheral devices to connect two drives to it at once, and with an adapter you can use a large connector to power a floppy drive. If you are using multiple adapters, make sure the total power is power supply is sufficient. The total load of the connectors connected to the splitter should not exceed the capacity of one connector.
Serial ATA power connector
The vast majority of modern hard drives and all SSDs are equipped with a SATA power connector. So, if a few years ago SATA connectors on power supplies were some kind of nice option, then on new power supplies they are mandatory. The SATA (Serial ATA) power connector is a special 15-pin connector that uses only five wires, which means that three pins per connector are connected to one wire. The total power supply through this connector is exactly the same as that of a conventional connector for peripherals, but the SATA cable is noticeably thinner.
SATA power connector
In the SATA power connector, each wire is connected to three contacts, and the numbering of the wires does not correspond to the numbering of the contacts. If your power supply is not equipped with SATA power connectors, you can use an adapter from a regular connector for peripheral devices. However, such adapters do not provide voltage on the +3.3 V line. Fortunately, this is not an issue for most SATA devices, since they do not use the +3.3 V line and only use +12 V and +5 V voltages.
Adapter from connector for peripheral devices to SATA
Additional power connector for PCI-E video cards
The ATX12V 2.x specification uses a new 24-pin motherboard power connector that provides more power to power various on-board controllers and PCI-E cards. The specification is designed for an additional 75 W of power directly for the PCI-E x16 slot and this power, in principle, is enough for many video cards with average performance. But high-end graphics cards typically require higher power levels. For this reason, the PCI-SIG (Special Interest Group) development group has introduced two standards for providing additional power to PCI-E video cards, which involve the use of the following connectors:
- PCI Express x16 Graphics 150 W-ATX - specification published in October 2004. An additional 6-pin (2x3) connector is used, which provides an additional 75 W of power. The total power of the PCI-E x16 slot reaches 150 W.
- PCI Express 225 W/300 W High Power Card Electromechanical - specification published in March 2008. Assumes the use of an 8-pin (2x4) additional power connector, providing an additional 150 W of power. The total power is 225 W (75+150) or 300 W (75+150+75).
To video cards that require even more energy, you can connect several connectors at once:
| PCI-E additional power connector configurations | |
| Maximum power | Additional configuration nutrition |
| 75 W | Not used |
| 150 W | 1 x 6-pin |
| 225 W | 2 x 6-pin or 1 x 8-pin |
| 300 W | 1 x 8-pin + 1 x 6-pin |
| 375 W | 2 x 8-pin |
| 450 W | 2 x 8-pin + 1 x 6-pin |
PCI Express cards are provided using 6-pin (2x3) or 8-pin (2x4) Molex Mini-Fit connectors, equipped with a female plug that connects directly to the video card. For reference, these connectors are similar to the Molex 39-01-2060 (6-pin) and 39-01-2080 (8-pin), but both use different keys to prevent the possibility of them being mistakenly installed in the +12 V connector on the motherboard board The following diagram shows the layout of the connectors, including the plug side. Pay attention to the "sense" signal on pin 5 - it allows the graphics card to determine whether the connector is connected. Without proper power levels, the card may shut down or operate in a mode with limited functionality. Also note that pin 2 is designated in the table as N/C (No Connection) according to the standard specification, but most power supplies seem to also supply +12 V.
6-pin additional power connector PCI-E 6 pin (2x3), rated for 75 W power
| Connector 6 pin (2x3) additional 75-W connector for powering the PCI-E video card | |||||
| Color | Signal | Contact | Contact | Signal | Color |
| Black | GND | 4 | 1 | +12 V | Yellow |
| Black | Sense | 5 | 2 | N/C | - |
| Black | GND | 6 | 3 | +12 V | Yellow |
The pin configuration on the 8-pin PCI-E additional power connector is shown in the diagram below. Please note that there is an additional +12 V voltage on pin 2 and two “sense” signals on pin 4 and pin 6, which allows the card to determine which connector is connected - a 6-pin or 8-pin - or whether there is no connection.
8-pin additional power connector PCI-E 8 pin (2x4), rated for 150 W power
| Connector 8 pin (2x4) additional 150-W connector for powering the PCI-E video card | |||||
| Color | Signal | Contact | Contact | Signal | Color |
| Black | GND | 5 | 1 | +12 V | Yellow |
| Black | Sense0 | 6 | 2 | 12 V | Yellow |
| Black | GND | 7 | 3 | +12 V | Yellow |
| Black | GND | 8 | 4 | Sense1 | Yellow |
The design of both connectors ensures backward compatibility: a 6 pin connector can be connected to an 8 pin socket. Thus, if your graphics card has a socket for an 8-pin connector, but the power supply is equipped only with a 6-pin connector, then you can connect it to the card by simply sliding it relative to the socket, as shown in the figure. The plug has a key design to prevent installation in an incorrect position, but when connecting the connector, you should avoid using excessive force, which may damage the card.
Connecting the 6-pin connector to the 8-pin socket on the graphics card
The signal contacts are located in such a way that the video card itself recognizes what type of connector is connected to the socket and, thus, how much power is available to it. For example, if a video card requires a full 300 W and has two 8 pin sockets (or 8 pin + 6 pin), but you use two six-wire connectors, the card will determine that it can only use 225 W and, depending on the design and firmware, may will either shut down or operate in reduced functionality mode.
Thanks to a special key on the plug, an 8-pin connector cannot be installed in a 6-pin socket. For this reason, many power supply manufacturers equip their products with "6+2" plugs, which allow you to disconnect an additional two if necessary, resulting in a regular 6-pin connector instead of an 8-pin connector. Such a connector, of course, will be installed without problems into the 6 pin socket on the board.
Attention! The 8-pin additional power connector for PCI-E cards and the 8-pin EPS12V standard CPU power connector use Molex Mini-Fit Jr. plugs that are similar in design. These plugs have different keys, but with some effort it may be possible to connect the EPS12V connector to the socket on the video card, or vice versa, connect the PCI-E power connector to the EPS12V socket on the motherboard. In any of these scenarios, the +12V pin will be connected directly to ground, which can lead to failure of the motherboard, video card or power supply.
The 6-pin connector uses two +12V pins to provide up to 75W of power, while the 8-pin connector uses three +12V pins to provide up to 150W. But according to the specification for Molex connectors, this set of pins allows for more power. Each pin on the PCI Express power connector can handle up to 8A of current when using standard pins - or more when using HCS or Plus HCS pins. If you multiply the contact power limits according to the specifications by their number, you can determine the connector’s ability to hold a current of a certain power:
| Maximum current power through the additional power connector of the PCI-E card | ||||
| Connector type | Number of contacts +12V | When using contacts contacts | When using HCS contacts | When using Plus HCS contacts |
| 6-pin | 2 | 192 W | 264 W | 288 W |
| 8-pin | 3 | 288 W | 396 W | 432 W |
In a 6-wire connector, the current is designed for two +12 V contacts, although most power supplies have three such contacts.
Standard Molex contacts are rated at 8A.
Molex HCS contacts are rated at 11A.
Molex Plus HCS contacts are rated at 12A.
All values are for a set of 4-6 Mini-Fit Jr pins. when using 18 gauge wires and standard temperatures.
Thus, although according to the specification the connectors are designed for a power of 75 (6 pin) and 150 W (8 pin), when using standard contacts the power can reach 192 and 288 W, respectively. By using HCS and Plus HCS contacts you can get even more power.
The two additional power connectors in question may appear in the documentation under the names PCI Express Graphics (PEG), Scalable Link Interface (SLI), or CrossFire Power Connectors, since they are used by high-end PCI-E x16 graphics cards that can work in conjunction with SLI or CrossFire. SLI and CrossFire are modes for using nVidia and AMD cards that allow you to combine cards in a bundle, using the computing resources of each of them to increase the performance of the graphics subsystem. Each card can consume hundreds of watts, which is why many high-end graphics cards have two or three additional power connectors. This means that most powerful
It's no secret that modern video card models consume a large amount of energy. Depending on the manufacturer, series, purpose and even a specific instance, power consumption can vary from several tens to several hundred watts. Where can you get such an amount of energy without depriving the other components of your system? Now we will tell you everything.Power for a fast modern video card can come from 3 sources:
| Power connector type | The power it provides |
| PCIe x16 | 75 W |
| 6-pin | 75 W |
| 8-pin | 150 W |
First, modern ones connect to the PCIe x16 expansion slot, which is powered by a 24-pin connector and provides graphics cards with up to 75 W of power. This turns out to be enough for beginner and intermediate levels. Such cards do not have additional power connectors and are not very demanding on the power supply, and, as a rule, provide relatively low performance.
PCIe x16 slot
Secondly, more powerful versions of video cards may have 2 types of power connectors: 6-pin and 8-pin, or both at once. The 6-pin connector provides the video card with additional power of 75 W, and the 8-pin connector provides 150 W. Thus, the maximum power consumption of a video card with 1 8-pin connector and 1 6-pin connector can reach the following value: 75 + 150 + 75 = 300 W (connector configurations may differ, including upwards). You should pay attention to the following fact: for each additional power connector on the video card, it must have a separate power connector. The presence of additional power connectors indicates both increased power consumption of the video card and greater performance (relative to video cards without additional power connectors and within one or two generations). In addition, by the presence of additional power connectors, you can approximately determine the power consumption for which it is designed. It is important to remember that if there are several power connectors on the video card, for normal operation of the computer it is necessary to connect a power cable to each connector. Otherwise, the computer will either not turn on or the video card will not operate at its maximum performance.
In this regard, it should be mentioned that they exist with separated 12 V power lines. This means that each connector (6-pin and 8-pin) will serve its own power line. You can read more about this in.
To summarize, to properly power your video card, you need to understand what power connectors it requires and what maximum power it consumes. Taking these factors into account will allow you to avoid an unpleasant situation in which your system cannot start due to lack of power or lack of necessary connectors. Enjoy the shopping!
If the video card has such a connector, then you need to connect additional power to it from the power supply.
Additional power is connected with a special adapter cable:
A 6-pin connector connects to the video card, and two molex-type connectors connect to the power supply.
Both connectors are connected to the power supply.
Black and brown ground, yellow +12 volts.
It should be taken into account that such video cards require increased power supply and it must be at least 350 W.
Modern power supplies already have a connector for additional power supply for the video card; in this case, there is no need for adapters.
Recently, video cards have appeared to which it is necessary to connect not a 6-pin power connector, but an 8-pin one.
This is due to an increase in power consumption by video cards.
These connectors have two more ground pins than 6-pin connectors.
If your power supply does not have such an output connector, then you need to purchase a 6-pin -> 8-pin adapter, but usually such an adapter comes with the video card.
You cannot connect a 6-pin connector instead of an 8-pin without an adapter.
For video cards that have two additional power connectors, you need to connect both connectors.
1.65 million hacked home computers are engaged in mining
Kaspersky Lab has published the results of its research, according to which there are 1.65 million hacked PCs in the world that are engaged in mining cryptocurrency for hackers.
It is noted that we are not talking only about home machines, but also about corporate servers.
The laboratory noted that the most popular malicious currency miners are Zcash and Monero.
The most popular currency is Bitcoin, but its mining is too inefficient on regular computers, unlike alternative currencies.
“The main effect on home computers or an organization's infrastructure is a decrease in performance,” said Kaspersky security expert Anton Ivanov, “Also, some miners may download modules from the infrastructure of a dangerous operation, and these modules may contain other malicious code such as Trojans.”
In most cases, the miner gets onto the computer using a specially created malicious program, the so-called dropper, the main function of which is to secretly install other software.
Such programs are usually disguised as pirated versions of licensed products or as activation key generators for them - users look for something like that, for example, on file hosting services and deliberately download them. But sometimes what they downloaded turns out to be not exactly what they wanted to download.
After launching the downloaded file, the installer itself is installed on the victim’s computer, and it already downloads the miner and a special utility to the disk that masks it in the system.
Also included with the program are services that ensure its autostart and configure its operation.
From malware droppers Kaspersky Internet Security will protect you by default - just make sure that the antivirus is always turned on, and such malware simply will not get onto your computer.
But miners, unlike droppers, are not malicious programs.
That's why they belong to a special category Riskware- Software that is legal in itself, but can be used for malicious purposes.
By default, Kaspersky Internet Security does not block or remove such programs, since the user may have installed them knowingly.
But if you want to play it safe and are sure that you are not going to use miners and other software that is included in the Riskware category, then you can always go to the settings of the security solution and find the section there Threats and detection and check the box next to the item Other programs.
If you're mining for someone else, you could end up with huge electricity bills and a noticeable slowdown in your PC and components.
LGA 1151 processor socket for Intel Coffee Lake has differences
The release of Intel Coffee Lake processors caused a storm of emotions among users and a flurry of discussions on various thematic resources, mainly due to the fact that they will only work with new motherboards, despite the LGA 1151 version that has been in use for a long time.
The real reason for the incompatibility has been revealed.
The thing is that the contacts on the new Intel processors are located in a different pattern than those on the Skylake and Kaby Lake processors, VideoCardz reports.
Intel has added more Vss (ground) and Vcc (power) pins to new processors.
The former were previously 377, but now there are 391.
The second ones are 128 and 146, respectively.
The total number of contacts has not changed, and remains at 1151, and all thanks to the reduction in the number of reserve contacts (RSVD) from 46 to 25.
The company reported that the eighth generation Core processors required additional and/or more stable power supply.
Although it was enough for the company to change the name to LGA 1151v2 to avoid the “righteous anger” of some users, it did not do this.
Wi-Fi hotspots in rural areas
The Rostelecom company reports a sharp increase in demand for wireless Internet access points built as part of a project to eliminate the digital divide in Russia.
The project in question involves the creation of Wi-Fi points in settlements with a population of 250 to 500 people.
Network access is provided at a speed of at least 10 Mbit/s.
At the end of July, Rostelecom announced the abolition of fees for connecting to the Internet through such hotspots.
Immediately after this, the demand for the service increased significantly.
The number of Internet sessions at access points jumped by 35%.
The total volume of Internet traffic at Wi-Fi points in August exceeded 1 PB for the first time, being 27% more than the month before.
As of June 30, 2017, universal communication services using Wi-Fi access points were provided in 4,690 settlements, which is 34% of the total plan (in total, almost 14 thousand points should be built by the end of 2019).
35 thousand kilometers of fiber-optic communication lines have already been laid.
Power connectors for peripheral devices In addition to connectors for the motherboard, all power supplies are also equipped with various additional connectors, most of which are intended for...
Power connectors for peripheral devices In addition to connectors for the motherboard, all power supplies are also equipped with various additional connectors, most of which are intended for...
CPU power connectors
Power to the CPU comes from a device called the Voltage Regulator Module (VRM), which is found in most motherboards. This device supplies power to the processor (typically through pins on the processor socket) and self-calibrates to ensure the processor is receiving the proper voltage. The VRM is designed to be powered by either +5V or +12V input voltage.
For many years, only +5V was used, but since 2000, most VRMs have moved to +12V due to the lower requirements for operating at that 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 until 2000). Whether the VRM on your board uses +5V or +12V depends on the specific board model and voltage regulator design. 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, we somehow came across a FIC (First International Computer) SD-11 motherboard equipped with a Semtech SC1144ABCSW voltage regulator. This board uses +5V voltage, 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 in the Slot A version and was specified to require 65 W of power at a nominal voltage of 1.8 V. 65 W at 1.8 V corresponds to a current of 36 ,1 A. When using a VRM with an input voltage of +5 V, a power of 65 W corresponds to a current of only 13 A. But this situation is obtained only under the condition of 100% efficiency of the voltage regulator, which is impossible. Typically, VRM efficiency is about 80%, so to ensure the processor and voltage regulator operate, the current must be approximately 16.25 A.
When you consider that other power consumers on the motherboard also use the +5V line - remember that ISA or PCI cards also use this voltage - you can see how easy it is to overload the +5V lines on the power supply.
Although most VRM designs on motherboards are derived from Pentium III and Athlon/Duron processors that use +5V regulators, most modern systems use VRMs rated at +12V because higher voltages reduce current levels. We can verify this using the example of the AMD Athlon 1 GHz, which was already mentioned above:
| Current level depending on input voltage | |||
| Power | Voltage | Current strength | Current in amperes, taking into account the efficiency of the voltage regulator 80% |
| 65 W | 1.8 V | 36.1 A | - |
| 65 W | 3.3 V | 19.7 A | 24.6 A |
| 65 W | 5.0 V | 13.0 A | 16.3 A |
| 65 W | 12.0 V | 5.4 A | 6.8 A |
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.
Thus, by connecting the VRM module on the motherboard to the +12V power line, we could gain a lot of benefits. But, as you already know, the ATX 2.03 specification assumes only one +12 V line, which is transmitted through the main power cable of the motherboard. Even the short-lived auxiliary 6-pin connector was deprived of contact with +12 V, so it could not help us. Drawing more than 8A of current through a single 18-gauge wire from the +12V line on the power supply is a very effective way to melt ATX connector pins, which are specified to handle no more than 6A of current when using standard Molex pins. Thus, a fundamentally different solution was required.
Platform Compatibility Guide (PCG)
The processor directly controls the current flowing through the +12V pin. Modern motherboards are designed to support as many processors as possible, however, the VRM circuits on some boards may not provide sufficient power to all processors that can be installed in the socket on the motherboard. To eliminate potential compatibility issues that could lead to PC instability or even component failure, Intel has developed a power standard called the Platform Compatibility Guide (PCG). PCG is mentioned on most Intel boxed processors and motherboards produced from 2004 to 2009. It was created for PC builders and system integrators to provide them with information about the power requirements of the processor and whether the motherboard meets these requirements.
PCG is a two- or three-character designation (for example, 05A), where the first two digits indicate the year in which the product was introduced, and an additional third letter corresponds to the market segment. PCG markings that include a third character A correspond to processors and motherboards belonging to the low-end market (require less power), while the letter B refers to processors and motherboards belonging to the high-end market segment (require more power ).
Motherboards that support high-end processors, by default, can also support lower-end processors, but not vice versa. For example, you can install a processor with PCG marking 05A into a motherboard marked 05B, but if you try to install a processor 05B into a board marked 05A, you may well encounter system instability or other, more serious consequences. In other words, it is always possible to install a less powerful processor on an expensive motherboard, but not vice versa.
| Recommendations for the power level on the +12 V line in accordance with the Intel Platform Compatibility Guide (PCG) marking | |||||
| PCG code | Year | Market segment | CPU Power Consumption | Direct current on the +12 V line | Peak current on the +12 V line |
| 04A | 2004 | Low-end | 84 W | 13 A | 16.5 A |
| 04B | 2004 | High-end | 115 W | 13 A | 16.5 A |
| 05A | 2005 | Low-end | 95 W | 13 A | 16.5 A |
| 05B | 2005 | High-end | 130 W | 16 A | 19 A |
| 06 | 2006 | All | 65 W | 8 A | 13 A |
| 08 | 2008 | High-end | 130 W | 16 A | 19 A |
| 09A | 2009 | Low-end | 65 W | 8 A | 13 A |
| 09B | 2009 | High-end | 95 W | 13 A | 16.5 A |
The power supply must be able to withstand a peak load of at least 10 ms.
A power supply that meets the required minimum +12V line can ensure stable system operation.
4-pin +12 V processor power connector
To increase the current on the +12V line, Intel created a new ATX12V power supply specification. This led to the appearance of a third power connector, which was called ATX +12 V and was used to supply additional +12 V voltage to the motherboard. This 4-pin power connector is standard on all motherboards that comply with the ATX12V specification 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 ATX motherboard power connector.
This connector has two +12 V contacts, each of which is rated for current 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 along the +12 V line. The pin locations of this connector are shown in the following diagram:
+12 V processor power connector, front view and pin layout
The assignment of contacts on the +12 V connector is presented in the following table:
| 4-pin +12 V connector for CPU power | |||||
| Contact | Signal | Color | Contact | Signal | Color |
| 3 | +12 V | Yellow | 1 | Gnd | Black |
| 4 | +12 V | Yellow | 2 | Gnd | Black |
Using standard Molex pins, each pin on the +12V connector can carry up to 8A of current, 11A with HCS pins, or up to 12A with Plus HCS pins. Even though this connector uses the same pins as the main connector, the current through this connector can reach higher values because fewer pins are used. By multiplying the number of contacts by the voltage, you can determine the maximum current power for a given connector:
Standard Molex contacts are rated at 8A.
Molex HCS contacts are rated at 11A.
Molex Plus HCS contacts are rated at 12A.
All values are for a set of 4-6 Mini-Fit Jr pins. when using 18 gauge wires and standard temperatures.
Thus, if standard contacts are used, the power can reach 192 W, which, in most cases, is sufficient even for modern high-performance CPUs. Consuming more power can lead to overheating and melting of the contacts, therefore, when using more power-hungry processor models, the +12 V plug to power the processor must include Molex HCS or Plus HCS contacts.
The 20-pin main power connector and the +12V processor power connector together provide a maximum current level of 443 W (using standard pins). It is important to note that the addition of a +12V connector allows you to use the full power of the 500W power supply without the risk of overheating or melted contacts.
Adapter for +12 V processor power supply connector
If power unit does not have a standard +12 V 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 might we encounter in this case?
The adapter connects to the connector for peripheral devices, which is found in almost all power supplies. The problem in this case is that the peripheral connector has only one +12 V pin, and the 4-pin CPU power connector has two such pins. Thus, if the adapter involves 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 only rated at 11A, loading more than this may cause the pins on the connector to overheat and melt. But 11 A is below the peak current values for which the connector pins should be designed in accordance with Intel PCG recommendations. This means that such adapters do not meet the latest standards.
We made the following calculations: considering VRM efficiency at 80%, for an average processor by today's standards, consuming 105 W, the current level will be approximately 11 A, which is the maximum for a peripheral power connector. Many modern processors have TDPs in excess of 105 W. But we would not recommend using adapters that use only one connector for peripheral devices with processors that have a TDP above 75 W. An example of such an adapter is shown in the following figure:
Adapter for CPU +12 V power connector from connector for powering peripheral devices
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, such boards are equipped with two sockets for a 4-pin +12 V connector, 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 aimed at file servers, the increased power demands of some high-end desktop processors have brought this 8-pin connector into the PC world.
8-pin +12 V CPU power connector. Front view and contact configuration
The pin assignments of the 8-pin CPU +12 V connector are given in the following table:
| 8-pin +12V CPU power connector | |||||
| Color | Signal | Contact | Contact | Signal | Color |
| Yellow | +12 V | 5 | 1 | GND | Black |
| Yellow | +12 V | 6 | 2 | GND | Black |
| Yellow | +12 V | 7 | 3 | GND | Black |
| Yellow | +12 V | 8 | 4 | GND | Black |
Some motherboards that use an 8-pin CPU power connector must have power supplied to all pins of the connector to operate correctly, while most motherboards of this type can operate 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 this connector configuration, you need to read the motherboard user manual - most likely, it will reflect whether one 4-pin power connector can be connected to an 8-wire socket on the board or not. If you are using a processor that draws more power than a single 4-pin power connector can provide, you will still need to find a power supply that has an 8-pin connector.
I was lucky enough to purchase an Nvidia GTX 780 video card instead of my old Nvidia GTX 560. The joy from the purchase did not last long, because... The video card refused to fit into my case. Although this problem can be quickly treated with the help of an angle grinder and straight hands)))
The next and main problem was the presence of two 8 pin connectors on the video card and their absence on the power supply. The unit I have is 700 W but it comes out with 2*6 pin.
First, let's turn to the theory, what kind of 8-pin connector is this? In essence, this is the same 6-pin connector only with the addition of two additional ground contacts. This is necessary to provide additional power to the video card via the 12V bus, which in turn is necessary for powerful video adapters, as well as for overclocking and using standard technologies such as AMD OverDrive.
After reading “smart” forums, I came to the conclusion that, in principle, the use of additional contacts is not mandatory, although desirable.
When trying to start the system, the video adapter generated an error about lack of power and refused to start the PC. It became clear that it was necessary to connect an eight-pin connector. In principle, there are adapters from 6 to 8 contacts, but firstly they cost money, and secondly you need to wait until they are delivered, and installing a new video card is “on fire” right now))).
Having studied the proposed adapter, it became clear that two additional contacts are simply duplicated from the existing ones.
It was also necessary to obtain a connector for connecting to the video card. The existing eight-pin adapter for powering the processor was perfect for this purpose. I simply sawed off the necessary parts that fit into the video card.
Now we needed to connect the connector to the power supply. It would have been possible to connect to 6 pin connectors, but I did not touch them, but cut off one unused SATA power connector and took two ground wires from there, and insulated the rest. And this is what happened.
