Cpu_Fan1, Sys_Fan1: Fan Connectors - MSI B450M-A PRO MAX II User 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.
You can control fans in BIOS> HARDWARE MONITOR panel. It allows you to set DC
or PWM to your fan type. Check the Smart Fan Mode, the fan speed will change
according to the CPU or system temperature. Uncheck the Smart Fan Mode, the fan
will spin at maximum speed.
⚠
Important
Make sure fans are working properly after switching the PWM/ DC mode.
CPU_FAN1
Fan connector specifications
Connector
CPU_FAN1
SYS_FAN1
PWM Mode pin definition
Pin
1
SYS_FAN1
3
Default fan mode
PWM mode
PWM mode
34
1
Signal Name Pin
Ground 2
Sense 4 Speed Control Signal
Max. current
1A
1A
Signal Name
+12V
Max. power
12W
12W