Detecting CPU throttling on over temperature
doconnor at gsoft.com.au
Thu Sep 10 02:48:10 UTC 2009
On Wed, 9 Sep 2009, Alexander Motin wrote:
> > around 100C. I did pull the c2d cpu docs at one point trying to
> > look at cpufreq. If you are bored, you can grab the docs from
> > intel and double check.
> AFAIR C2D supports three protection technologies. When CPU is hot, it
> starts reducing frequency (multiplier) and voltage, alike to IEST. If
> it is insufficient, it starts to skip core cycles, alike to TCC. If
> it is still insufficient and temperature rises above about 100C,
> emergency shutdown happens.
Hmm, I have since realised it's an E2140 which doesn't have Core2Duo
branding (I don't know if it really IS one or not).
On the bench here I could not observe an effect by running
dd if=/dev/zero bs=128k count=5000| md5
in a loop and checking the frequency with
However the idle time seemed to go up, but only to 10% or so, it was
Still, now I have been reminded of coretemp I can monitor it
on "suspect" systems :)
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
-- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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