Cpu_Fan1, Sys_Fan1~2: Fan Connectors - MSI H270M PRO-VDH Mode D'emploi

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.
PWM Mode fan connector
1
CPU_FAN1
1 Ground
3 Sense
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.
2 +12V
Speed Control
4
Signal
There are gradient points of the fan speed that allow you to
adjust fan speed in relation to CPU temperature.
DC Mode fan connector
1
SYS_FAN1
1 Ground
3 Sense
1
SYS_FAN2
Voltage
2
Control
4 NC
Rear I/O Panel
13