Re: [gentoo-user] CPU "choking" under high load

[Johannes Kimmel]

Paul Hartman wrote:
> On Fri, Mar 26, 2010 at 5:43 PM, Dale <rdalek1967@×××××.com> wrote:
>> Daniel Quinn wrote:
>>> I don't know if this is a hardware issue or not, but I thought that maybe
>>> I'd
>>> configured my kernel incorrectly and that this might be a known issue
>>> someone
>>> here has run across in the past so here goes:
>>>
>>> My computer is a pretty impressive AMD 64 X2 Dual Core Processor 6400+ box
>>> with 2GB of RAM and for the most part, I just use it to write code at
>>> work.
>>> However, whenever I'm doing something CPU-intensive, two things happen:
>>>
>>>   * The load on the box goes up to 4
>>>   * The box intermittently wobbles from running at full-speed and dropping
>>> to
>>>     a crawl.  This is best seen while watching Flash videos online,
>>>     compressing/encoding video, or compiling.  Everything is fine for a
>>> few
>>>     minutes, then suddenly the rate of compiling/compression/playback etc.
>>>     drops to a crawl for about 1-3minutes, then back up to full speed.
>>>
>>> I don't know why it's happening.  I've tried various kernel options with
>>> no
>>> change in behaviour.  Outside of that though, I don't know what to try.
>>> Suggestions welcome :-(
>>>
>>>
>> Shot in the dark here.  Could it be that something is getting hot, or thinks
>> it is getting hot, and slows down processing in a effort to cool things down
>> a bit?  I don't know if this is just laptops but I think there is a option
>> in the kernel to do this.  I don't use it but it may be worth checking into.
>>   Maybe it was turned on by default.
>
> Sometimes in the BIOS this happens, too. At work a few years ago we
> had a Dell laptop where it thought the temperature was 200C degrees
> all the time, so it would run the fan at full speed and go into
> lowest-power mode etc. Once we determined it wasn't really 200C, we
> found out it was a buggy BIOS and upgrading it solved the problem.
> Nobody knows why the laptop worked fine for 2 years and then suddenly
> exhibited this problem, but I was glad to get it fixed so I would stop
> hearing the fan blowing at max speed in the cubicle next to mine. :)
>

I have the very same problem with my GX700 msi laptop. I determined the 
   cause was a dirty cooler. Every time I blow the dust out of the fan 
it can run hours without throttling itself.

If maybe your cpu-cooler is undersized and has collected a lot of dust, 
cleaning it could solve your problem.

Johannes