How/why would dev.cpu.0.freq_levels change??!?

[David Wolfskill]

On Mon, Jun 30, 2008 at 03:11:11PM -0400, John Baldwin wrote:
> ...
> Are you sure it is really a problem?  Presumably the machine is overheating or 
> something that is causing the BIOS to request that the CPU speed is lowered 
> (I wonder if Windows changes CPU speed when _PSS changes so that the  BIOS 
> writer figured changing _PSS was sufficient to force the CPU to be 
> throttled).  Presumably if the BIOS really is trying to protect the hardware 
> not doing what it wants might result in physical damage to the machine of 
> some sort.

Yeah, I'm pretty sure.  Evidence:

* The behavior is markedly different from what it had been up to about a
  week ago.  In particular, building RELENG_6, RELENG_7, and HEAD daily,
  the fans would normally vary in speed (based on pitch & intensity of
  sound, rather than from a sysctl variable) generally in an "expected"
  way based on the reported CPU temperature (this was from sysctl
  variable).

  Now, in contrast, the machinee runs for a bit, then the fans kick in,
  the CPU acts as if it maxes out at half speed.  And the *only* way I've
  found to even slow the fans down is to power-cycle -- even though the
  reported CPU temperature is way low -- around 45C.  (Exhaust air from
  the fans isn't especially warm, either.)

* As a result, a full "make buildworld" takes several hours longer than
  it did as recently as a week ago.

* I am now able to reproduce the problem just booting the machine to the
  BIOS config/setup stage.

* The fan noise is freaking annoying.  :-/

In any case, I've dropped the machine off for hardware repair.  I should
soon find out whether "repair" is a feasible option or I should look at
replacement.

Thanks for all your help!

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
I submit that "conspiracy" would be an appropriate collective noun for cats.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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