Detecting CPU throttling on over temperature

Daniel O'Connor doconnor at
Thu Sep 10 13:32:52 UTC 2009

On Thu, 10 Sep 2009, Thierry Thomas wrote:
> > I recently discovered a system where the floppy drive cable was
> > intermittently fouling the CPU fan - I believe this caused the CPU
> > to overheat and then get throttled by the BIOS.
> >
> > Does anyone know if it is possible to determine if this is the
> > case? ie is there a way to be informed if throttling has occurred?
> Have you tried the ports sysutils/lmmon and sysutils/wmlmmon?
> Some others exist under /usr/ports/sysutils, but I don't use them.

Those tools are usually very difficult to get to work unless you can get 
information from your motherboard maker because various voltage 
dividers are set by the mobo maker..

In any case measuring the temperature is only a proxy, direct (rate 
limited!) notification of the throttling even would be better.

Daniel O'Connor software and network engineer
for Genesis Software -
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
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