Asus Z8PE-D12 - Manual (Page 35)

ASUS Z8PE-D12 Series 2-15
3. Repeat steps 1 to 3 to install the other heatsink if you have installed a second Repeat steps 1 to 3 to install the other heatsink if you have installed a second
CPU, then connect the fan cable to the other 4-pin connector.
3. Connect the fan cable to the 4-pin connector labeled CPU_FAN1 or
CPU_FAN2 depending on the CPU socket you install.