This 6-pin connector is also sometimes used to provide extra power to high-end video cards. On motherboards, the more common connector used for this purpose is the ATX 4-pin Power Connector, used either by itself or with a second 4-pin connector, creating an 8-pin connector. The terms “PCI Express cables” or “PEG cables” (for PCI Express Graphics) are sometimes used to describe a 6-pin 12V power connector.
ATX 6-pin 12V Power Connector Pinout (ATX v2.2)
Below is the pinout for the standard ATX 6-pin (3x2) 12V power connector as of Version 2.2 of the ATX Specification (PDF).
Using an ATX 6-pin 12V Power Connector
The 6-pin 12V power connector is used to power PCI Express expansion cards that require more power than their expansion slots can provide, which is 75 watts. Some video cards, for example, draw more than 75 watts, in which case connecting a 6-pin 12V power cable can provide more power to the card. Video cards sometimes come with an 8-pin connector if they can utilize more power than what a 6-pin cable can provide. If this is the case, but you only have a 6-pin 12V power connector, a 6-pin one will fit but won’t provide any more than what the 6-pin provides. Unfortunately, even though a smaller cable fits, some cards simply won’t work properly without the full power provided by an 8-pin connector. Be sure to check your video card’s documentation to see if this 6-instead-of-8-pin configuration will work for you. Some power supplies come with a 6+2 PCI Express power cable, which is a cable that has both a 6-pin power connector and an additional 2-pin power connector semi-attached, which can either be combined to become an 8-pin ATX cable or kept separate to work with 6-pin-only connections. If you have a power supply that has two free 4-pin molex power connectors, but your video card requires a 6-pin 12V power connector, you can use an adapter.
