Fan speed nearly constantly at 100% [Solved]

azripah · 2012-06-21 15:24:38

I've been having problems with my desktop recently, in particular with the CPU fan. When I boot it up, everything's fine, but within 5 minutes, the fan is at 100% regardless of processor load- major issue, because at max speed, the fan is ridiculously loud (>40db). I've been testing out what was on the wiki on the relevant article, but the information, or some of it at least, seems to be a bit dated with regard to directory structure.

I suspect a failed heat sensor might be to blame, because of my 3 temp inputs, 2 are locked at 0 and 34 degrees, and the third suspiciously exactly mirrors my graphics card's temperature, the graphics card being designed to run hotter than the CPU.

I'm mainly just looking for a workaround fix to make my computer more tolerable in what are probably my last 2 or 3 months before upgrade. Perhaps something like locking the fan speed at 60%.

It is kept in a room that is very rarely above 30C, ventilation is excellent, and removing the sides of the case to further ventilate did nothing. So I don't think the CPU is actually running at 70C (requirement for 100% fan speed) after being on for 5 minutes.

EDIT: Opened my case and actually felt my heatsink/fan for science. No way it was above 50C. Something's not right with the software, I now know for sure.

Last edited by azripah (2012-06-24 04:30:44)

Trilby · 2012-06-21 15:46:27

On workaround (very dangerous if the temps are actually high) is to echo speeds to the approproate file in /sys/class/*.

I believe the directory structure under sys/class can vary based on the hardware ... but don't quote me on that. It does seem to vary a bit between a couple of my machines. However, a quick exploration of that directory should lead you to the fan speed files, perhaps under 'thermal', sometimes under 'platform'.

When you hit the right directory, there should be a few relevant files, one with the current speed, one with a max speed (these will likely hold the same value for you right now), and several with different thresholds. You should be able to echo a number (speed) to the cur_state/cur_speed file and change the speed.

You'll likely have to put this echo command in rc.local to make it last across boots.

azripah · 2012-06-24 04:30:28

Yeah, sorry about this entire post. I just broke down and decided to replace the fan. I opened the thing up. It had probably a half centimeter of dust caked up on the heatsink. Come to think of it, I don't think I've cleaned that thing in over 4 years. I clean it up, sure enough, the computer's whisper quiet once more.

To be honest, it's probably best I was never able to figure out how to adjust fan speed- probably would have burnt out my poor little processor.

Last edited by azripah (2012-06-24 04:31:40)

Arch Linux

#1 2012-06-21 15:24:38

Fan speed nearly constantly at 100% [Solved]

#2 2012-06-21 15:46:27

Re: Fan speed nearly constantly at 100% [Solved]

#3 2012-06-24 04:30:28

Re: Fan speed nearly constantly at 100% [Solved]

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