Difference in fan speed between Windows and GNU/Linux

Question

On my Dell Vostro 200 (2.2GHz Core 2 Duo, 4GB ram) there's very noticeable difference in fan noise (and thus fan speed?) between WinXP and Ubuntu 10.04. I'ts a dual boot setup, and the fans (or at least one of the fans?) make more noise when using the Linux install. Since I use Linux most of the time, it'd be nice if I could bring down the fan noise. When booting the fans start running fast, as is expected, and gradually slow down, to end up at a reasonably low speed. When booting into WinXP I can hear the fans slow down in steps -- this does not happen to the same extend in Ubuntu.

I've tried running 'fancontrol', but its config application (pwmconfig) tells me

/usr/sbin/pwmconfig: There are no pwm-capable sensor modules installed

Any clues as to what else I can try to fix the problem? There don't appear to be any BIOS settings regarding fan speeds on this machine.

[Update] So I opened up the case, turns out it's the fan on the GPU (ATI RV610 [Radeon HD 2400 XT]) that's making the noise.

Solution 1

I had loud fan noise too upon a new install of Linux Mint 13, an Ubuntu derivitive, but when I install the "additional drivers" in the form of the nvidia video driver, the fan speed goes back down to normal volume, i.e., I can hardly hear it now. Point being it's the video card fan and not the CPU fan. At least for me.

Solution 2

If it's the Graphics card fan, then it's pretty likely it's related to the driver. Is there a more recent driver you could use, or tweaks that you could make to the fan performance ?

Solution 3

If the fans are only louder in Linux and not actually at their maximum, my guess would simply be that the Linux you are using is more CPU intensive than Windows XP, which casues higher heat, which causes the fans to be on longer.

If however the CPU is at near 0% in Linux and/or higher in Windows, my only guess could be that Dell have some sort of driver or program that runs in Windows and somehow controls the fans.

But, most programs within Windows (and Linux that I have seen) are simply are one way - tell you heat levels and fan speed/status, they cannot actually change the fan as this is just controlled from the BIOS or other hardware.

Comments

[Dillawes0me]

Excellent question! I had been thinking of this too - are CPU fans more efficient with Windows running?

[Andreas Rehm]

If your gpu is the problem: please check if you use a propper driver - using the frambuffer could use more cpu and gpu speed than a propper driver.

[klokop]

I'm currently using the 'radeon' driver from 'xserver-xorg-video-radeon'. Tried using 'xserver-xorg-video-radeonhd', but it sucked. In the past I've had bad experiences with AMD/ATI's proprietary driver, so I'm not using that. Ah well.

[klokop]

I figured out that it's the Graphics Card fan that's running so loudly. It seems to be running at max speed.

[klokop]

I wasn't talking about a laptop.