[SOLVED] Asus motherboard not recognizing 4 pin fan header. Treats it as 3 pin header

digitalgriffin

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TLDR: Is there some setting that allows you to change the motherboards 3 pin fan setting to 4 pin?

I have an older Asus Z77 Sabertooth motherboard. I'm in the process of replacing some of the components. I've been replacing the 3 pin fans with 4 pin fans. I know the motherboard is designed to handle both and regulate the fan speeds of both (via PWM 3 pin and 4 pin) However the motherboard is still treating the 4 pin fans like 3 pins even after FanXPert tuning. Normally this wouldn't be a problem, however the Fan's RGB's are powered via the motherboard, and they aren't lighting up because the motherboard is pulsing the power at too low a rate.
 

digitalgriffin

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Figured it out.

ASUS implements a pseudo 4 pin support by supplying +5V to the 4th pin 100% of the time. It does not pulse.

The speed is them controlled via PWM via the fan supply voltage pin. So it wouldn't matter if a 3 pin or 4 pin were plugged in. Only the CPU fans implement a true 4 pin Fan header support.

Bummer.
 

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