Intel ATX Specification 2.03

ATX AUX 6-Pin Auxiliary Power Connector Pinout

The ATX AUX connector added extra 3.3 V and 5 V current next to the 20-pin main plug on demanding motherboards of the late 1990s. Select a contact to see its role.

Before you wire

  • It is keyed on pin 6 and wired with 16 AWG cable; it powers only the extra 3.3 V and 5 V current, not the whole board.

Pin assignment

Pin 1: GND1Pin 2: GND2Pin 3: GND3Pin 4: +3.3V4Pin 5: +3.3V5Pin 6: +5V6Pin 1: GND1Pin 2: GND2Pin 3: GND3Pin 4: +3.3V4Pin 5: +3.3V5Pin 6: +5V6
  • Ground
  • Power

Schematic face view, not to scale · numbering per Intel ATX Specification 2.03

Pin assignment of ATX AUX 6-Pin Auxiliary Power Connector
PinSignalFunctionStatus
GNDGround returnStandard
GNDGround returnStandard
GNDGround returnStandard
+3.3V+3.3 VDCStandard
+3.3V+3.3 VDCStandard
+5V+5 VDCStandard

Pin details

Select a pin on the diagram or table for full details.

Pin details

About this connector

Six-contact auxiliary ATX power connector with three ground returns, two +3.3 V contacts and one +5 V contact for 250 W and 300 W motherboards.

Notes

  • Intel recommended it for motherboards that need a 250 W or 300 W supply (ATX 2.03, section 4.2.1).
  • It disappeared when ATX12V 2.0 moved to the 24-pin main connector and shifted processor power to 12 V.

Common use cases

  • Late-1990s and early-2000s ATX motherboards with high 3.3 V and 5 V loads

Specifications

Standard
Molex 90331-0010 keyed pin 6 or equivalent, 16 AWG
Positions
6

Primary sources

Help keep this page accurate

Checked this pinout against your board or connector? Confirm it, or report a pin, voltage or orientation that does not match.

Report a problemConfirm this pinout

Opens a public form on GitHub with this page already filled in; a free GitHub account is needed. How reports and confirmations work