Difference Between 3 Pin And 4 Pin Fan Connectors

The so called pwm line uses the pwm mechanism to adjust the fan speed and the fan voltage is constant avoiding the control voltage to shift.

Difference between 3 pin and 4 pin fan connectors.

Most motherboards have 4 pin for the cpu. It will also have three square holes on the front and three wires entering the back. Three wire and four wire fan connectors. A 4 pin pwm fan connector will have four square holes on the front and four wires entering the back.

Chassis and processor fans use either a three wire or four wire connector. Connecting a 4 pin fan to a 3 pin socket. Changes can easily cause the fan to stall or modulate erratically if the voltage isn t correct. The 3rd pin feeds rpm information back to the motherboard.

The 4 pin cooling fan is based on the 3 pin and has a pwm line pulse width modulation. The three wire connectors are for small chassis fans with lower power consumption. With a three pin connection two are voltage and one is a speed sensor. 4 pin fans or pwm fans don t have this issue as the 4th pin on the fan allows voltage changes to be made more quickly and less erratically.

A motherboard controls speed by intermittingly sending a current pulse to the fan. The 4th pin sends a signal to the fan to change speed allowing the fan to run slower and. The pwm control wire will not be connected so the fan speed cannot be controlled. Line up the guides on the connector to the tab on the socket.

A 3 pin fan connector will be smaller in size than the 4 pin pwm fan connector. 2 pins provide electricity to turn the fan. If you connect a 4 pin fan on a 3 pin socket the fan will run at maximum speed.