Power Supply Fan - Linux vs Windows

[EtherCircuit]

Hi,

I am a new linux user dual booting Red Hat 9 and Windows XP.

When I run Windows the power supply fan runs full power during boot up, then calms down once the OS is loaded.

When I run Linux the power supply fan runs full speed all the time and never calms down like it does in Windows. (very loud and kinda annoying)

I couldn't find any switches on the power supply, and I couldn't find any power supply fan options in my bios, windows, or red hat.

Does anyone have any suggestions on how to fix this so that the fan calms down once Linux is running?

Thanks,
Jason

[Dolda2000]

I can't really explain why it settles down when Windows loads. Is this fan connected to your mobo?

[EtherCircuit]

Hey Dolda,

This fan in question is connected to the power supply, I can take the power supply out of the computer and the fan is inside with it. (This is how I tested that this was the fan causing the loud noise, I took it out of the computer and booted each OS to see how it reacted.) This is different than the fan that is on top of the main processor.

Please help if you can! Thanks,

Jason

[Dolda2000]

Are you really sure that was the one? It is not possible to turn off the power supply fan from the operating system. The PSU fan is most often always on, and in some cases regulated by a thermostat or a PTC resistor, but even in the latter cases, these components only measure the temperature of parts inside the PSU, and I simply cannot believe that Windows actually makes the PSU run cooler. Actually, I hardly think it's possible for any OS to accomplish that. It's indeed possible to make the CPU run cooler though. If that was the case, your Linux kernel was probably not compiled with APM support.

[nomar]

I have a kind of similar problem.

I have issues with the layout of hardware in my case I sort this out sometime!

Anyway the problems I have mean that the PSU becomes hot due to heat drawn off the CPU heatsink. I have this problem in Windows and in Linux - however when Windows is left idle it shuts enough of the hardware down to reduce the internal temp of the PSU and therefore the fans slows down and produces less noise.

From what I can gather Linux, though efficent with regards to CPU when idle doesn't shutdown as much hardware, and I don't know how to or if I can change this - as far as I know Redhat doesn't quite have ACPI support yet and this may be the issue. Becouse of this the PSU fan remains at high speed constantly.

This may have something to do with your problem.

nomar.