Re: [gentoo-user] Re: lm_sensors much hotter in 2.6.31 than 2.6.28

[Grant]

>> After upgrading from 2.6.28 to 2.6.31, I noticed my CPU temperatures
>> are reported a full 20C hotter.  If I load the old kernel, the
>> reported temperatures drops back down to normal.  Has anyone else seen
>> this?
>
> If you're using coretemp as sensor, the temps are always off (the coretemp
> sensor of Intel chips is not accurate, not by any stretch of the
> imagination.)  It only reports the distance to the CPU's maximum thermal
> junction, which then the coretemp driver *tries* to translate into a
> temperature, but the result is wrong since the value reported by the CPU is
> not accurate to start with (it only gets accurate as you approach the max
> value).  That maximum value is totally undocumented for desktop CPUs (the
> docs Intel provided recently are wrong.)
>
> You should use your mainboard's sensors instead for accurate values.

I'm actually using k8temp.  Do you think it is susceptible to the same
problems you're talking about?  I also have an ACPI sensor available
named THRM.  Should that one be more accurate?

BTW, another system of mine (Dell laptop) only seems to have available
coretemp or an ACPI sensor which reports values like 46960 mWh.  Am I
totally out of luck with that one?

So, In the end, it's fairly impossible to monitor a CPU's actual
temperature in order to keep it below the published maximum?

- Grant