No powerNow/cpufreq for a desktop Athlon-XP ?

[Bruno Ducrot]

On Mon, Nov 14, 2005 at 09:56:58AM +0100, Thierry Herbelot wrote:
> Hello,
> 
> I'm using FreeBSD 6.0 on an Athlon-based desktop machine. I have loaded the 
> acpi and cpufreq kernel modules, but powerd does not want to start :
> 'powerd: lookup freq: No such file or directory'
> 
> From a little googling, it seems that cpufreq will not work on this machine as 
> PowerNow is active only on mobile Athlons (see for example 
> http://forums.pcper.com/showthread.php?t=357591)
> 
> Am I correct ? or is there any way to enable powernow on a desktop Athlon ?
> 

Some people reported that it's possible to use powernow on athlon-based
desktop (report under Linux).  I don't know the full detail though, but
IIRC you have to buy a low-powered processor, and change the driver code
in order to add the differents entry for the differents states
available.  On the other hand, it is not possible to change the
voltages associated (this require a special VRM part, available only
on mobile systems).
I'm sure this would not save power then (especially because all
athlon-xp support a very good C2 power state), though this
will likely allow you to cool the processor.

Cheers,

-- 
Bruno Ducrot

--  Which is worse:  ignorance or apathy?
--  Don't know.  Don't care.