Rear I/O Panel
CPU_FAN1, SYS_FAN1~2: Fan Connectors
Fan connectors can be classified as PWM (Pulse Width Modulation) Mode and DC 
Mode. PWM Mode fan connectors provide constant 12V output and adjust fan speed 
with speed control signal. DC Mode fan connectors control fan speed by changing 
voltage. Therefore, when you plug a 3-pin (Non-PWM) fan to a PWM Mode fan 
connector, the fan speed will be always maintained at 100%, and that could be noisy.
1
CPU_FAN1
1 Ground 2 +12V
3 Sense 4
Speed Control 
Signal
1
SYS_FAN1
1
SYS_FAN2
1 Ground 2
Voltage 
Control
3 Sense 4 NC
PWM Mode fan connector DC Mode fan connector
Switching fan mode and adjusting fan speed
You can switch between PWM mode and DC mode and adjust fan speed in BIOS > 
HARDWARE MONITOR.
Select PWM mode or DC mode
 Important
Make sure fans are working properly after switching the PWM/ DC mode.
There are gradient points of the fan speed that allow you to 
adjust fan speed in relation to CPU temperature.