Connections to the Motherboard 6500648 160W Power Supply The P1 power connector that leads from the computer’s power supply plugs into the power supply connection on the motherboard. Although Pin 1 is marked on the motherboard, match the clip on the connector to the notch on the motherboard power supply connection. The clip is on the backside of the connector. The P6 power connector is a 4-pin auxiliary power connector that connects only to motherboards that support Pentium™ IV and Pentium™ IV-based Celeron™ processors. It supplies the additional power required by Pentium™ IV-based processors require.