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Have something to add to the explanation? Sound off in the comments. Source: Three Wire and Four Wire Fan Connectors Note: When connecting a three wire fan to a four pin fan header, the fan is always on there is no fan control.Ī four wire fan connecting to a four pin fan header:Ī four wire fan connecting to a three pin fan header: The four wire connectors are for processor fans with higher power consumption.Ī three wire fan connecting to a four pin fan header: The three wire connectors are for small chassis fans with lower power consumption. With this type, fan speed is typically controlled by increasing or decreasing the voltage over the power wire.Ī four pin connector is a little different than the three pin connector since it has the extra (fourth) wire used for controlling and sending signals to the fan, which likely has a chip on it that tells it to slow down or speed up (in addition to the other wires the three pin connector has).Ĭhassis and processor fans use either a three wire or four wire connector. The pinouts for the 4 pin fan cable connector are: Apple Motherboard 4 pin CPU PWM fan connector pinout Apple Motherboard 4 pin CPU PWM fan connector pinout HP Server 5 pin Fan connector pinout Motherboard 4 pin CPU PWM fan connector pinout Motherboard 4 pin CPU PWM fan connector pinout There is one linked connector - 4 pin motherboard fan. The signal wire measures how fast the fan is moving without any controls for the fan’s speed. SuperUser contributor Homey_D_Clown_IT has the answer for us:Ī three pin connector is basically power (5/12 volt), ground, and signal.

Download 4 pin fan pinout