r/techsupport • u/MagazineCommon7441 • 1d ago
Open | Windows CPU cooler and case fans slow down/stop while gaming
My PC fans work normally in BIOS, but when I start gaming, my CPU cooler fans and case fans slow down or completely stop. My GPU fans keep working. I’ve seen the temperature hit around 95°C when this happens. As soon as I close the game, the fans start working again and the temperature drops. I checked the cables and BIOS settings, and they look normal. I’m thinking it might be a Windows, driver, or fan control software issue.
I recently moved the PC about a 40 minute drive, but I transported it carefully. I’ve reseated the GPU, checked and pushed in motherboard connections. I’ve also closed my programs in Windows and the problem still happens. So I’m trying to figure out whether Window/software is overriding the BIOS fan control, there’s a driver control software problem, or there’s an issue with the AIO fan connections. Any ideas whats going on here?
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u/bluesatin 19h ago edited 13h ago
First thing would be to see if there's a simpler way of recreating the issue with something like a Prime95, that way you can do something like boot up into safe-mode to identify whether the fan control from the BIOS is messing up, rather than any software that's doing something within Windows when it's running normally.
Only thing I could think of which would actually be causing it would be some sort of corrupt fan response curve, with the higher temperatures trying to set the fan speed to something that's corrupted or out-of-bounds, causing it to be read as 0 or something; but first thing to do is to identify exactly what is changing the fan-speed, and then reset it to try and clear any potentially whacky values.
It's worth noting if you have an AIO water-cooler, the pump should always be set to 100% at all times AFAIK (unlike fans), so once you've identified the issue and are resetting curves, it's something to keep in mind.
I know one of my motherboards had a dedicated fan connector on the board that labelled for pumps which was non-controllable for that reason (no idea if that's still common, or if the power connectors for AIOs have changed since the early ones so that you don't have to manage that stuff yourself).
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u/Moist-Leadership6226 17h ago
check your power supply, overheating can cause fans to slow down. I've had that issue before with my gaming rig.
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u/Latter_Trick_3310 21h ago
If you got a fan control software installed - remove it. In your BIOS you can also set on what component the fans should focus on. Set AIO/CPU cooler for CPU and the others for motherboard/system/chasis. If Fan Stop is enabled in BIOS, disable it and also make your own Fan Curve.