amdtemp does not find my CPU.

Jim Ohlstein jim at
Sat Mar 16 19:59:38 UTC 2013

On 3/16/13 2:24 PM, Don Lewis wrote:
> On 16 Mar, Jim Ohlstein wrote:


>>> On Fri, Mar 15, 2013 at 03:16:19PM -0400, Jim Ohlstein wrote:


>> Note the big change between lines 34 and 35.
> My FX-4100 behaves the same way.  I noticed it because on an idle system
> 	sysctl -a | grep amdtemp
> would read consistently higher than
> 	sysctl dev.amdtemp
> I think the thermal sensor in this AMD CPU family has a much faster
> response time so that it is more sensitive to temperature changes caused
> by CPU load over the short term.  Going from idle to 100% CPU load for
> even 0.1 seconds and then back to idle is likely to change the die
> temperature a lot, but will probably only have a negligible effect on
> the heat sink temperature.  The faster response time may be needed to
> support AMD Turbo CORE.

That's very possible. This is not an idle system so I cannot really test
that out without taking it offline. My results on that comparison are
therefore perhaps not valid. However, I don't see much difference. See

When I stress the CPU the temps simply stay high without any
fluctuation, but do show those rapid rises both before and after. This
supports your explanation.

Of course this still does not explain the observed differences between
the two modules on the other machine.

Jim Ohlstein

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