[Soekris] Core temp observations
soren at soekris.com
Thu Jan 19 17:59:45 UTC 2012
Are Tysland wrote:
> Just thought I'd share my temperature observations on a net6501-70 with
> fresh install of Debian Testing (Wheezy).
> Samples are taken with lm-sensors. Kernel is 3.1.0-1-amd64.
> Ambient temperature varies between 23°C and 24°C.
> No internal hard drive mounted yet.
> All numbers are taken at least 2 hours after the values has stabilised.
> Placed flat on a table:
> When idle: 83°C
> With a load at ~4: 86°C
> Placed horizontally raised 10cm from table surface:
> When idle: 80°C
> With a load at ~4: 83°C
> Placed vertically with holes on both sides free:
> When idle: 75°C
> With a load at ~5: 78°C
> I'm not sure the values are correct as I have no way of confirming
> them, but I find the differences interesting.
Current lm-sersors don't seems to be correct on a net6501. You can use
the builtin digital sensor on the Atom chip, in an earlier post:
According to the Intel docs, the commercial Atom E6xx parts we use have
a Tjmax of 90°C, with an onchip precision digital thermal sensor that
will shut down the chip if the Tjmax is exceeded.
The die temperature is readable using RDMSR reg 019C bits 16..22, as an
offset from Tjmax, can be done in the comBIOS monitor by:
> rm 19c
If it t.ex. shows 00000000 88240000 then the offset is the 24 (hex),
which gives 90 - 36 = 54°C
Our testing shows net6501-70 processpr temperature about 32 deg celcius
above ambient when in the standard case flat on a table.
CEO & Chief Engineer
Soekris Engineering, Inc.
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