Re: powernow-k8 manual voltage selection ?

[Nebojsa Trpkovic <trxman@gmail.com>]

Bruno Ducrot wrote:

>How you have done this?  By powernow-k8 or via BIOS setting?  If the
>latter, I will not trust this input yet. You can verify this is OK via
>cpufrequtils at
>http://www.kernel.org/pub/linux/utils/kernel/cpufreq/cpufrequtils-0.1.tar.bz2
>then go to cpufrequtils-0.1/debug/x86_64 and issue a make, then ./powernow-k8-decode
>as root.  You must have the msr kernel driver loaded to get it working.
>  
>
I've done that by some software tool in window$ (I just didn't want to 
lock up system several times in my Gentoo :) ). By that tool (can't 
remember name) I was able to change multiplicators and voltages. I was 
monitoring voltages by other 2 tools and I could saw that my mobo 
overvolts CPU a little bit under heavy load, but it's about ~0.000V 
@0.800V, ~0.025V @1.100V and ~0.050V @1.5V
I've tried to undervolt in BIOS and it worked, too. But, my BIOS allows 
only 0.9V and by software I was able to go under that voltage. Here you 
can see results (all of them passed few hours in prime):

http://www.aaen.edu.yu/~tnt/graf.png

Now, I'm running at 2.385MHz at 1.425V and under full load my lm_sensors 
show VCore = 1.46V

I'll try to play a little bit more when I get 1 x 512MB module, as my 
mobo would lock up every time I try to change something on the fly with 
2 modules. It's comon issue with Socket 754 boards.

>Such patch will never reach mainline (but may be posted to this list for
>reference purpose only).
>  
>
Yes... I guess so... I'm a little bit sad because linux becomes such 
conservative...

Regards,
Nebojsa