MSI B550-A PRO User Manual - Page 36

CPU_FAN1, PUMP_FAN1, SYS_FAN1~6: 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. The auto mode fan connectors can automatically detect PWM and DC mode. However, you can follow the instruction below to adjust the fan connector to PWM or DC Mode manually. SYS_FAN6 CPU_FAN1 PUMP_FAN1 SYS_FAN1 SYS_FAN2 Connector CPU_FAN1 PUMP_FAN1 SYS_FAN1~6 Default fan mode Auto mode PWM mode DC mode Max. current 2A 3A 1A Max. power 24W 36W 12W SYS_FAN3 SYS_FAN5 SYS_FAN4 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 There are gradient points of the fan speed that allow you to adjust fan speed in relation to CPU temperature. ⚠⚠Important Make sure fans are working properly after switching the PWM/ DC mode. Pin definition of fan connectors 1 PWM Mode pin definition 1 Ground 2 +12V 3 Sense 4 Speed Control Signal 1 DC Mode pin definition 1 Ground 2 Voltage Control 3 Sense 4 NC 36 Overview of Components