# ACPI CPU fan speed

## wilsonsamm

How can I get my puter to slow the fan down when the CPU is idling, or cool?

My CPU fan seems currently to be in a permanent state of "on". It's jolly noisy since there is a blade that's hitting against the duct tape that's holding it on.

EDIT: I forgot to mention, I have ACPI support in the kernel, and acpid installed and running, it's just that I've no idea how to configure this.Last edited by wilsonsamm on Thu May 27, 2010 6:52 am; edited 1 time in total

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## DaggyStyle

you've ducked taped your hsf? why?

try looking in the bios.

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## wilsonsamm

 *DaggyStyle wrote:*   

> you've ducked taped your hsf? why?

 

Yes, well my previous fan snapped a blade off! But this replacement fan actually doesn't match the holes in the heatsink for the screws. Electrically it's fine though. And I'm on the budget of a British student so I haven't splashed out on a brand new heatsink and all the rest of it.

 *DaggyStyle wrote:*   

> try looking in the bios.

 

Thanks, I will do. I think I remember looking there before, but to no avail. I'll have another look when I reboot this afternoon.

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## DaggyStyle

 *wilsonsamm wrote:*   

>  *DaggyStyle wrote:*   you've ducked taped your hsf? why? 
> 
> Yes, well my previous fan snapped a blade off! But this replacement fan actually doesn't match the holes in the heatsink for the screws. Electrically it's fine though. And I'm on the budget of a British student so I haven't splashed out on a brand new heatsink and all the rest of it.
> 
>  *DaggyStyle wrote:*   try looking in the bios. 
> ...

 

I'm a student too (not british) so I understand where you are coming from but I highly recommend you'll muster some cash and get a new matching hsf .

using a broken one is highly unrecommended especially on a intensive os such as gentoo.

if you can post the type of cpu or better yet, your mb type, I'd try and look for a descend cheap hsf for you to consider.

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## wilsonsamm

Thanks a lot  :Smile: 

I have the AMD Sempron, socket AM2. My motherboard is from VIA.

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## wilsonsamm

Am I even barking up the right tree with acpid and co?

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## DaggyStyle

if you can afford it, here is my favorite, it can be used in newer cpus too.

http://www.scan.co.uk/Products/Arctic-Cooling-Freezer-7-Pro-v2-S1366-A1156-S775-AM3-AM2plus-AM2-939-Up-to-130-Watts!

http://www.amazon.co.uk/gp/offer-listing/B002G392ZI/ref=asc_df_B002G392ZI664074?ie=UTF8&condition=new&tag=geizhals07-21&creative=7978&creativeASIN=B002G392ZI&linkCode=asm

if you can't what's the budget?

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## wilsonsamm

Ah, that's good. Thank you for that link. I can't really see if that's the three-wire one or the new kind of four-wire one, either is fine my motherboard supports them both.

I might buy it at some point. first priority after food and such is replacing my laptop's hard disk though...

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## jfp

 *Quote:*   

> How can I get my puter to slow the fan down when the CPU is idling, or cool? 

 

Back to the original question.

My laptop (intel based) exhibits what I think is a similar problem (no I do not have any duck tape installed).

After a reboot, the fan is either off completely or very slow. If, however, I compile something big (e.g. PyQT4), the fan (understandably) speeds up to high. The problem is that the fan never returns to low of off, even if the cpu temp returns to a low temperature... It just stays high until I reboot.

Does anyone have any idea why this is happening?

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## alexdu

 *jfp wrote:*   

>  *Quote:*   How can I get my puter to slow the fan down when the CPU is idling, or cool?  
> 
> Back to the original question.
> 
> ...
> ...

 

I have a lenovo laptop and since kernel 2.6.32.6+ and CONFIG_PM_RUNTIME=y and CONFIG_USB_SUSPEND=y in the kernel config the fan stops completely if the CPU has no load. It never stopped before...

I am not sure if it helps everybody, especially for guys with desktops, but you can try.

I will post full kernel config if it needed.

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## Ant P.

emerge lm_sensors and play around with the pwmconfig script.

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## jfp

 *Quote:*   

> I have a lenovo laptop and since kernel 2.6.32.6+ and CONFIG_PM_RUNTIME=y and CONFIG_USB_SUSPEND=y in the kernel config the fan stops completely if the CPU has no load. It never stopped before... 

 

I tried setting both of those option on my HP dv6000 laptop. Sadly, on reboot I got a kernel "Oops". I did not try setting just one of the parameters at a time, so I don't know which caused me a problem.

However, I did find something. Yesterday I was working in a non-graphical environment. (i.e. KDE was not running). In this case, the CPU fan worked perfectly. That is it would go high when a lot of work was going on and go to low or off when the laptop was idle.

Based on that I assume there problem has something to do with kde and it's power management.

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