Gigabyte GA-A75N-USB3 User Manual page 47

CPU Smart FAN Mode
&
Specifies how to control CPU fan speed. This item is configurable only if CPU Smart FAN Control is set
to Enabled.
Auto Lets the BIOS automatically detect the type of CPU fan installed and sets the optimal CPU

fan control mode. (Default)
Voltage Sets Voltage mode for a 3-pin CPU fan.

PWM Sets PWM mode for a 4-pin CPU fan.

- 47 - BIOS Setup