ACPI is not working

[Nate Lawson]

On Wed, 5 May 2004, Christian Uhrhan wrote:
> > You can put that in /etc/sysctl.conf if it works ok.  Make sure it works
> > before doing that though.  It should lower the temps with no real
> > performance hit (unlike throttling).
>
> thx very much, after rebooting the fan slowed down and then came back to
> full speed. after setting hw.acpi.cpu.cx_lowest to 1 and a few more
> seconds it slowed down again and it is working (at the moment i will
> obeye it for a while before add it to /etc/sysctl.conf as you told me)
> under X too.

Good.  That should be fine.

> > Your system does not support throttling.  It has a 0 for duty_width.
> > However, it does support ACPI performance states so once the driver is
> > finished for those, you will be able to step back your clock to save
> > power/heat.  That's a different and better mechanism than throttling
> > anyway.
>
> hmmm...i guess i missunderstood something. isn't throttling == stepping
> back the cpu speed (for instance from 1000MHz to 500MHz)?
>
> thank you for looking at my problem and thanks that you invested some
> time to help me

Throttling does step back the effective CPU speed by triggering the CPU
clock at some fraction of the actual clock.  See a previous post I made
for more techical details.  As Bruno said, you have a mobile athlon and so
powernow or acpi performance states will provide clock/voltage control.  I
haven't finished the drivers for that for FreeBSD yet but his driver
should help you if you want to try it.  Clock/voltage control is similar
but different than throttling.

-Nate