6 pin ATX auxiliary power connector.
The ATX auxiliary 6-pin power connector is an optional supplemental connector defined in the Intel ATX and ATX12V Power Supply Design Guide specifications. It was introduced to supplement the 20-pin main ATX connector on high-current platforms that required more than 18 A on the +3.3 V rail or more than 24 A on the +5 V rail. The connector uses a Molex Mini-Fit Jr. housing (cable side: Molex 90331-0010) and carries three ground returns alongside two +3.3 V supply wires and one +5 V supply wire, each circuit rated at 5 A. Its use was most common during the late 1990s to early 2000s era of high-power platforms where the main connector alone could not satisfy total rail current demands.
| Pin | Name | Color | Description |
|---|---|---|---|
| 1 | COM | black | Ground |
| 2 | COM | black | Ground |
| 3 | COM | black | Ground |
| 4 | 3.3V | orange | +3.3 VDC |
| 5 | 3.3V | orange | +3.3 VDC |
| 6 | 5V | red | +5 VDC |
Signals
- COM — Ground return (pins 1, 2, 3); three ground wires distribute return current across the connector.
- 3.3V — +3.3 V supply (pins 4, 5); orange wires supplementing the +3.3 V rail on the main 20-pin connector when load exceeds 18 A.
- 5V — +5 V supply (pin 6); red wire providing additional +5 V capacity when load exceeds 24 A.
Notes
The auxiliary connector is only required when the +3.3 V load exceeds 18 A or the +5 V load exceeds 24 A; it is absent on power supplies and motherboards that do not need the extra current capacity. Each circuit is rated at a maximum of 5 A. The cable-side housing is Molex 90331-0010, with pin 6 keyed to prevent incorrect insertion. The connector uses the same Molex Mini-Fit Jr. 4.20 mm pitch housing family as the main ATX power connector. Note that the Molex part number 15-48-0106 listed in some sources for the motherboard header belongs to the older AT-era connector family; the ATX12V v1.3 specification identifies the cable-side housing as Molex 90331-0010 for this auxiliary connector.
Connector part numbers
- Cable connector: Molex 90331-0010
- Terminals: Molex 08-50-0276
- Maximum current per circuit: 5 A