CPU Overheating?

[illoai at gmail.com]

On 30 March 2014 20:11, Walter Hurry <walterhurry at gmail.com> wrote:
> I have a bog-standard Acer laptop with FreeBSD 9.2 (amd64).
>
> CPU is  AMD Athlon(tm) 64 X2 Dual-Core Processor TK-42 (1596.09-MHz K8-class CPU) per dmsg.
>
> From time to time, it shuts off without warning, as if the power cable has been pulled out. Nothing in any of the logs, and when I power up again it starts normally after replaying the journal.
>
> The shut-off is invariably when it is doing a compile of a big port. I therefore suspect that the CPU is overheating and that the BIOS is causing the shutdown.
>
> To investigate the problem, I have done a 'kldload coretemp' and am periodically running:
>  'sysctl hw.acpi.thermal.tz0.temperature'. So far (only 6 runs) this is reporting temperatures between 76C and 84C.
>
> Question 1: Is this the canonical way to monitor CPU temperature?
> Question 2: Is this too hot?
> Question 3: I plan to load the module in /boot/loader.conf and set up a cron job to run every minute and log the result to a file. Is this sensible, or overkill?
>

amdtemp.ko should give you a bunch of new sysctls under
'dev.amdtemp' to monitor

84°C is too hot for a desktop processor, & pretty close to too hot
for a laptop.  With decent airflow I only rarely get above 75°C
on my laptop.  Things do have to be disassembled & cleaned
from time to time, though.

It's not such a bad idea to run a script to log those values every
minute or so if you suspect overheating.  You'll probably lose
the last value or two when your machine shuts off, though.
Maybe write the output to a file on an nfs server?  Or get an
old dot-matrix printer & log to that?

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