Cpu_Fan1, Sys_Fan1~4: Fan Connectors - MSI 970A Manual

CPU_FAN1, SYS_FAN1~4: Fan Connectors

Fan connectors can be classified as PWM (Pulse Width Modulation) Mode and Voltage
Mode. PWM Mode fan connectors provide constant 12V output and adjust fan speed
with speed control signal. Voltage 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.
Controlling the fan speed
There are two ways to manage fan speed. One is to go to BIOS > HARDWARE
MONITOR. The other is to use COMMAND CENTER application.
Both methods offer gradient points of the fan speed that allow you to adjust fan speed
in relation to CPU temperature.
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Overview of Components
PWM Mode fan connector
1
3
Voltage Mode fan connector
1
3
1
3
BIOS > HARDWARE MONITOR
1
CPU_FAN1
Ground 2
Sense 4
1
SYS_FAN1/ SYS_FAN2
Ground 2
Sense 4
1
SYS_FAN3/ SYS_FAN4
Ground 2
NC
COMMAND CENTER
+12V
Speed Control Signal
Voltage Control
NC
+12V