Cpu_Fan1, Sys_Fan1: Fan Connectors - MSI B365M PRO-VD Manual

CPU_FAN1, SYS_FAN1: Fan Connectors

Fan connectors can be classified as PWM (Pulse Width Modulation) Mode or 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. When you plug a 3-pin (Non-PWM) fan to a fan connector in PWM mode, the
fan speed will always maintain at 100%, which might create a lot of noise. You can
follow the instruction below to adjust the fan connector to PWM or DC Mode.
Default PWM Mode fan connectors
Default DC Mode fan connectors
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.
Pin definition of fan connectors
PWM Mode pin definition
1 Ground
3 Sense
14
Rear I/O Panel
There are gradient points of the fan speed that allow you to
adjust fan speed in relation to CPU temperature.
2 +12V
Speed Control
4
Signal
1
CPU_FAN1
1
SYS_FAN1
DC Mode pin definition
1 Ground
3 Sense
Voltage
2
Control
4 NC