Management of Thermal

[Mel]

On Thursday 11 October 2007 01:25:57 Norberto Meijome wrote:
> On Wed, 10 Oct 2007 14:59:05 +0200
>
> Mel <fbsd.mobile at rachie.is-a-geek.net> wrote:
> > Experience with a HP laptop shows this to be not true. It currently is
> > working perfectly with a laptop cooling pad and not going anywhere near
> > critical values, but before that, we had to use the following in
> > /etc/sysctl.conf to prevent the computer from locking up (I suspect that
> > the Intel CPU shuts itself down before burning out):
> > hw.acpi.thermal.user_override=1
> > hw.acpi.thermal.tz0._PSV="75C"
> > hw.acpi.thermal.tz0._CRT="80C"
> >
> > These values are 5C lower then detected values. I started with 10C lower
> > and reached critical too early. 5C works perfectly. Logging the temp[1]
> > each minute I could see the effect of the cooling fans once it reached
> > 75C.
>
> Hi Mel,
> from man acpi_thermal
>      hw.acpi.thermal.tz%d._PSV
>              Temperature to start passive cooling by throttling down CPU,
> etc. This value can be overridden by the user.
>
> which implies is at what temperature it'll use methods other than the fans
> to cool down.
>
> Your experience seems to contradict this (*._PSV = temperature at which
> fans kick in)  ? thanks,

Yes. I never saw cpu frequency change or performance degrade, but fans did 
kick in. I cannot say with certainty that the fans did not kick at this point 
before I changed this value, but no more lock ups and also no critical 
warning/shutdown. Trust me, not for lack of trying.

I gotta say though, that a laptop cooling pad works wonders. Machine has been 
running tinderbox > 36 hours, compiling kde/openoffice and such, meanwhile 
running desktop applications on the 2nd core and it's at 55 at idle times 
~60C when really busy. Quite a difference.
-- 
Mel