This connector supplies additional +12 V power to a PCI Express graphics card. A x16 slot delivers at most 75 W, so high-power cards draw the rest from one or more auxiliary connectors; the 6-pin connector provides up to a further 75 W. Because graphics cards draw most of their current from the 12 V rail, every contact on this connector is either +12 V or ground. It is formally the PCI Express 150 W-ATX (2×3) auxiliary power connector, and is commonly called a “PEG” cable, where “PEG” stands for PCI Express Graphics.
6 pin PCIe power connector at the cable.
| Pin | Name | Color | Description |
|---|---|---|---|
| 1 | 12V | yellow | +12 V |
| 2 | 12V | yellow | +12 V |
| 3 | 12V | yellow | +12 V |
| 4 | GND | black | Ground |
| 5 | Sense | black | Tied to ground at the PSU; lets the card detect the connector |
| 6 | GND | black | Ground |
Notes
- A x16 slot supplies up to 75 W; this 6-pin connector adds up to a further 75 W of +12 V, giving a 150 W card total.
- Pin 5 is a Sense contact tied to ground in the power supply (or jumpered to an adjacent ground pin). The card uses it to confirm that the auxiliary connector is plugged in. Although its wire is black like the grounds, it is a separate signal in the specification.
- The connector is keyed so a 6-pin (2×3) plug can seat in an 8-pin (2×4) socket, but an 8-pin plug cannot be forced into a 6-pin socket. The 8-pin connector carries two sense pins and signals that up to 150 W is available; with only a 6-pin attached, the card limits itself to 75 W.
- Each contact is rated at 8.0 A maximum at +12 V (all six energised). The connector is built on the Molex Mini-Fit Jr. series.
Signals
- +12V — +12 VDC main power (pins 1–3), up to 8.0 A per contact.
- GND — power return (pins 4 and 6).
- Sense — pin 5; tied to ground at the supply so the card can detect that the connector is fitted.
Connector part numbers
- Video card connector: Molex 45558-0002
- Cable connector: Molex 45559-0002
- Terminals: Molex 39-00-0168, Molex 44476-1111
- Maximum current per circuit: 8 amps
References
- Intel ATX Version 3.0 Multi Rail Desktop Platform Power Supply Design Guide — PCIe add-in card connectors — 6-pin/8-pin pin-out, 75 W rating, 8.0 A per contact and the sense-pin detection mechanism.
- PCI Express Card Electromechanical (CEM) Specification, Revision 3.0 (PCI-SIG) — defines the 150 W-ATX auxiliary power connectors.