If I connect this splitter to a Motherboard 4 pin PWM connector and connect 2, 3 Pin Chassis fans will the connected 3 Pin fans speed be controlled by the speed signal coming off the 4 Pin Motherboard connector ???

Question

If I connect this splitter to a Motherboard 4 pin PWM connector and connect 2,  3 Pin Chassis fans will the connected 3 Pin fans speed be controlled by the speed signal coming off the 4 Pin Motherboard connector ???

Accepted Answer

4-pin fans allow Pulse Width Modulation (PWM) to control fan speed. This is a digital process most notably found on CPU fan headers. 3-pin headers will control fan speed through the use of variable voltage, an analog process. Most chassis fan headers use this method, even if they have all 4 pin connections. There is a chance that the chassis fans run in PWM mode, meaning that the fans would run at 100% all the time without the 4th pin, but you would have to look up the specifics of your board to be sure. Often times, your BIOS or fan software will support modifications through advanced options in UEFI.

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