PWM (DC pulse width modulation) mode: The motherboard controls the fan speed through pulse signals. This mode is usually supported by a 4-pin fan.
DC (DC with RPM monitor) mode: The motherboard controls the fan speed by adjusting the voltage. Ordinary 3-pin fans use this relatively simple way to control the speed.
2.PWM is a more advanced and reasonable speed control method. According to the temperature of the temperature sensor, the motherboard can select the best rotation speed within the rotation speed range of the fan to achieve the best heat dissipation effect. Generally speaking, only the graphics card and CPU fan support PWM mode, and the cooling fan of chassis power supply supports DC mode.
3. If the fan supports PWM mode, it should use PWM mode instead of DC mode.