Page 41 of the user manualATX 4-Pin 12V Power (PWR 4P) (Optional)ATX PWR 4P (OPTIONAL), the 4-pin ATX 12V power connection(s), is used to provide additional power to the CPU. Some power supplies provide a dedicated 4-pin CPU ATX power connector, while other power supplies split an 8pin EPS connector into a 4+4 pin connector; either of these 4-pin power connector are proper connectors for this port.This secondary power connector is optional to provide additional power for improved overclocking. Please remember to make sure that the tab on the ATX socket is aligned with the release clip on the cable. NOTE: If the tab and release clip are on opposite sides, powering on the system WILL damage the board. Please review installation instructions from your power supply manufacturer to verify which connectors may be used for the CPU power.