user undervolting

dgaffuri · Advocate Joined: 05 Jun 2005 Posts: 2078 Location: Italy

Hi, and thanks to you for all your work

bdz · Posted: Fri Jan 13, 2006 7:24 pm Post subject:

OK, thank you for the confirmation. So now the HowTo is correct about your CPU model.

Just a wild question to anyone who read this:
How many of you would be interested by a sysfs interface to change the number of entries in the frequency table and the frequency value of each entry? I mean a full dynamic configuration of all the parameters of the frequency/voltage setpoints array, not only the voltages values as with my current patch version.

BDz

Phlogiston · Posted: Mon Feb 13, 2006 9:51 am Post subject:

A general question about undervolting: It's not a good idea or nearly impossible to use undervolting togethre with a cpu freq scaling governor such as the conservative?
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dgaffuri · Advocate Joined: 05 Jun 2005 Posts: 2078 Location: Italy

Phlogiston · Posted: Mon Feb 13, 2006 12:35 pm Post subject:

rschwarze · n00b Joined: 01 Jul 2005 Posts: 63 Location: Germany

cpufreq already changes the voltages of your pemtium m.

with the standard settings, the voltages for a standard pentium m are between 980 and 1340 mv and cufreq changes them when it changes the frequency.

with our undervolting patch, we are able to see this voltages and to change them to much lower voltages, myvoltages are now between 700 and 970.

if you like to try it out, just go to http://gentoo-wiki.com/HOWTO_Undervolt_a_Pentium_M_CPU and follow the instructions. before any voltage is changed, you are able to have a look at the voltages your system is currently using. then you can deside if you want to change them.

Greetz, Roman

dgaffuri · Advocate Joined: 05 Jun 2005 Posts: 2078 Location: Italy

Phlogiston · Posted: Mon Feb 13, 2006 2:16 pm Post subject:

dgaffuri · Advocate Joined: 05 Jun 2005 Posts: 2078 Location: Italy

Phlogiston · Posted: Mon Feb 13, 2006 4:02 pm Post subject:

bdz · Posted: Mon Feb 13, 2006 7:05 pm Post subject:

rschwarze · n00b Joined: 01 Jul 2005 Posts: 63 Location: Germany

if you test each voltage/frequency pair for at least one two hours or so with gimps, you are on the safe side. should not be to difficult to write a script that does that over night. so it will not cost you too much time.

and some settings are pretty easy: i have never seen someone who couldn't use 700mv at the lowest frequency, so you can at least try that out. that gives you lots of power saving in idle mode

From my point of view, it is totally worth the effort. my notebook was really hot and loud before and now its cool and quiet. And that's very imprtant for me, cause i don't like the noise of a fan when i just surf the internet.

So long,

Roman

Phlogiston · Posted: Wed Feb 15, 2006 1:35 pm Post subject:

Ok guys. I felt boring and started undervolting

First I used the values from the wiki:

bdz · Posted: Wed Feb 15, 2006 7:19 pm Post subject:

Great!

It's always good to hear a new succes story with the patch.

One smal remark about your voltages. If you look at the actual values that are used you wil see that they are not exactly what you have set
You should see something like this:

Phlogiston · Posted: Wed Feb 15, 2006 7:32 pm Post subject:

rschwarze · n00b Joined: 01 Jul 2005 Posts: 63 Location: Germany

Like I said! everybody loves undervolting

you said something about a script which controls your fan. how are you doing that? it's probably only working with supportet fans?

thx for an answer

cu, roman

bdz · Posted: Wed Feb 15, 2006 7:50 pm Post subject:

Phlogiston:
Yes that's me that started writing this patch and the howto. But some parts are strongly inspired by some previous work of some other guys.
And now Roman (rschwarze) has joined me to work on the next version of the patch.
Also several people have added their contribution to the howto.

(If anybody else wants to join the team you're welcome. Just let us know)

Phlogiston · Posted: Wed Feb 15, 2006 7:55 pm Post subject:

Phlogiston · Posted: Wed Feb 15, 2006 7:56 pm Post subject:

bdz · Posted: Wed Feb 15, 2006 8:20 pm Post subject:

soulwarrior · Guru Joined: 21 Oct 2002 Posts: 331

I am too running this patch successfully

It's a Intel Pentium M 740 with the following values for the voltage table:

"956,956,956,956,956,956,956,828,732,700"

Greetings,
soulwarrior

bdz · Posted: Wed Feb 15, 2006 9:29 pm Post subject:

Thank you very much for your voltages soulwarrior. I have added them to the howto.

Phlogiston · Posted: Wed Feb 15, 2006 10:41 pm Post subject:

bdz · Posted: Wed Feb 15, 2006 11:27 pm Post subject:

Yes I forgot about nice.
But if you want to test indermediate frequencies you will need to use userspace grovernor :wink:

Phlogiston · Posted: Wed Feb 15, 2006 11:49 pm Post subject: