Re: cpu temperature readings

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sun, 2 Jul 2023 11:43:35 +0200
    From:        Michael van Elst <mlelstv%serpens.de@localhost>
    Message-ID:  <ZKFGx7KLzIBefLOY%serpens.de@localhost>

  | Yes. That bit also triggers powerd.

So my current guess (and it is no more than that) would be that if
powerd happens to notice that happening, which would require it to
look at just the right time, then powerd does a system shutdown.
If powerd doesn't notice quickly enough, the CPU (or BIOS perhaps)
sees that things are getting too hot, and no-one is taking any corrective
action, and simply kills the power.

That would explain the shutdown types I'm observing.

  | It's also possible that the heat sink needs attention (re-apply thermal
  | paste or similar), this might prevent the CPU from reaching a critical
  | temperature.

That's possible - but the reason I haven't really been looking at the
cooling system (which is, after all, the obvious place to look) is that
when things are legitimately hot (when the CPU really is working hard)
it seems to be very effective in cooling it again, quite quickly.

I suppose it is possible that when the temp rises very rapidly, very
quickly, as in when doing CPU intensive work, at high speed, the cooler
also ramps up, and cools at max rate, whereas when the CPU temp just
creeps up slowly, the cooler doesn't notice it happening, and fails to
react - but that seems kind of unlikely to me,   It certainly doesn't
seem like the kind of problem that can be caused by thermal paste (or
the lack thereof).

But I really know nothing about any of the factors involved here.

kre