AMD Family 10h cpufreq driver

[fluffles.net]

cpghost wrote:
> On Tue, Sep 23, 2008 at 08:45:59AM +0900, G. Otsuji wrote:
>   
>> Hi,
>> I foget to say that debug.cpufreq.lowest=1200 in 
>> /boot/loader.conf and running powerd is my stable state.
>>     
>
> I didn't test your patch yet, but this is the lowest freq I can
> use on my
>   AMD Phenom(tm) 9350e Quad-Core Processor (2000.08-MHz K8-class CPU)
> running
>   FreeBSD 7.1-PRE as of Sept 5.  (/i386 *and* /amd64)
>
> If I go below that, the system freezes hard, and I have to power cycle
> the motherboard to recover. But, again, this is without your patch.
> I look forward to test it as soon as I can. :)
>   

This may also be a hardware issue. Some buck converters on the
motherboard's VRM (Voltage Regulator Module) do not like switching from
very low idle drain to much higher one very quickly. I had one user
report about that who uses Windows.

Have you tried switching manually gradually down without any load? You
need to change the debug.cpufreq.lowest together with dev.cpu.0.freq

Also, it would be nice if i could see the voltage levels somewhere (in
sysctl?), but i haven't found it yet.

Cheers,
Veronica