powernow-k8 manual voltage selection ?

[Nebojsa Trpkovic]

Hello.

I just got my new box and I'm testing it all day long :)
It's Socket754 AMD Athlon (Newcastle) 3000+. I've spotted that it can run stable (>=1h in prime95) at voltages much lover than it's by default. Default is:
1.500V @2.0GHz
1.100V @1.0GHz
And my tests show something like this (I haven't tested all frequencies yet):
1.525V @2.5GHz
1.400V @2.4GHz
1.325V @2.3GHz
1.250V @2.2GHz
1.200V @2.1GHz
1.150V @2.0GHz <---
1.075V @1.9GHz
... and so on.

My question is:
Is there some way (PATCH) to specify manualy voltages for every FID my CPU can run?
I don't care if it's command line argument while loading powernow-k8 module or it's some kind of hack within powernow-k8.c source, as long as it works :)

Thank you.
Regards,
Nebojsa

P.S. Don't worry, I wouldn't use exact "minimum" voltage, but for example 1.200 - 1.250V @2.0GHz

[Bruno Ducrot]

Hi,

Post by Nebojsa Trpkovic
Hello.
I just got my new box and I'm testing it all day long :)
... and so on.

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.

Post by Nebojsa Trpkovic
Is there some way (PATCH) to specify manualy voltages for every FID my CPU can run?

This has been discussed some times ago. You have to do it yourself (or
maybe ask someone to give you some advice or browse the cpufreq archive,
etc).
Such patch will never reach mainline (but may be posted to this list for
reference purpose only).

Cheers,

[Nebojsa Trpkovic]

Post by Bruno Ducrot
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):

Loading Image...

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.

Post by Bruno Ducrot
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

[Bruno Ducrot]

Post by Nebojsa Trpkovic

Post by Bruno Ducrot
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
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

Could you please ./powernow-k8-decode in this case (nb:
powernow-k8-decode do not need powernow-k8).

Post by Nebojsa Trpkovic
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.

Post by Bruno Ducrot
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...

linux have been always conservative in mainline if running hardware
out-of-spec AFAIK.

Cheers,

[Bruno Ducrot]

Post by Bruno Ducrot
linux have been always conservative in mainline if running hardware
out-of-spec AFAIK.

I forgot to attach this patch. You have to modify it to suit your
needs, though.