Power Supplies - Upgrading and Repairing PCs - page 900

standard defines a 6-pin (2x3) auxiliary power connector capable of delivering an additional
75W to a graphics card directly from the power supply, for a total of 150W to the card.
• PCI Express 225 W/300 W High Power Card Electromechanical Specification —Published
in March 2008, this standard defines an 8-pin (2x4) auxiliary power connector capable of
supplying an additional 150W of power, for a total of either 225 watts (75+150) or 300 watts
(75+150+75) of available power.
Cards requiring even more power can use multiple connectors, as shown in Table 18.19 .
Table 18.19. Graphics Card Auxiliary Power Connector Configurations
The PCI Express auxiliary power connectors are 6-pin (2 × 3) or 8-pin (2 × 4) Molex Mini-Fit Jr.
connector housings with female terminals that provide power directly to a video card. For reference,
the connector is similar to Molex part number 39-01-2060 (6-pin) or 39-01-2080 (8-pin), but with
different keying to prevent interchanging them with the +12V motherboard power connectors. A
diagram of the 6-pin connector is shown in Figure 18.34 , and the pinout in Table 18.20 . Note the
Sense signal at pin 5, which allows a graphics card to detect whether a 6-pin power connector has
been attached. Without the proper power connections being detected, the card may shut down or
operate in a reduced functionality mode. Also note that pin 2 is technically listed as “no connection”
in the official specification, but most power supplies do seem to include +12V there.
Figure 18.34. PCI Express 6-pin (2×3) auxiliary 75W power supply connector.
Table 18.20. PCI Express 6-Pin (2×3) Auxiliary 75W Power Connector Pinout (Graphics Card
Socket)
A diagram of the 8-pin connector is shown in Figure 18.35 , and the pinout in Table 18.21 . Note the
additional +12V power at pin 2 and the two Sense signals at pins 4 and 6, which allow a card to