Difference between revisions of "Talk:Pentium M undervolting and underclocking"

From ThinkWiki
Jump to: navigation, search
m (Unrecognized processors)
(Various speedstep-cetrino notes)
Line 45: Line 45:
  
 
----
 
----
== Unrecognized processors ==
+
== Trouble loading modules ==
Alas, I still can not use the speedstep-centrino module on my T43p - it will not recognize my processor and load the appropriate /sys/devices../cpufreq knobs.  However, acpi-cpufreq works nicely.
+
If you receive the error after applying the bdz patch:
 
+
If I try to load the (patched by method #2) speedstep-centrino module with
+
 
+
{{cmdroot|modprobe speedstep-centrino}}
+
 
+
I am given...
+
  
 
     FATAL: Error inserting speedstep_centrino
 
     FATAL: Error inserting speedstep_centrino
 
     (/lib/modules/2.6.15.4/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device
 
     (/lib/modules/2.6.15.4/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device
  
...don't really understand it - the T43p uses the (Dothan) Pentium M processor, mine is the 2.13 MHz version.  Looking through the code, I don't see why it should complain (appears Banias CPUs are recognized -> anything else is Dothan).  Any ideas - I'll look into BIOS settings(?).  Others with a T43(p) - does bdz-patched speedstep-centrino load for you without difficulty?
+
be sure you have included "ACPI tables" for decoding valid frequency - voltage pairs.
  
Update - figured it out - you still have to include the ACPI tables option with bdz's patched centrino module - note that some of the documentation explicitly noted removing this option.
+
Also, note you may have to manually "modprobe" the speedstep-centrino during your boot sequence.  For some reason it won't autodetect on my debian sid system.
  
Wow - underclocking results in a *noticably* cooler processor, approximately 3-5 degrees, which is often enough to have the fan stop (now 43 deg basal temp on my lap.)  The battery life boost is much more modest, I'm down to 18.5 W/h now with everything off.
+
Underclocking results in a *noticably* cooler processor, approximately 3-5 degrees, which is often enough to have the fan stop (now 43 deg basal temp on my lap.)  The battery life boost is much more modest, I'm down to 17.5 W/h now with everything off.
  
 
--[[User:gsmenden|gsmenden]] 23:50, 12 Feb 2006 (EST)
 
--[[User:gsmenden|gsmenden]] 23:50, 12 Feb 2006 (EST)

Revision as of 08:26, 15 February 2006

Hei Thinker,

according to my notion of the character of this page, i thought it should possibly be renamed to something like "How to lower voltage and clock speed on Pentium M processors" ("lower" might be replaced by "finetune" or "manually lower" or "tweak" or something else expressing more the expert audience of the article). This has the following advantages:

  • complies with the naming scheme ;-)
  • has words more likely to be found in google (voltage vs. undervolting; clock, speed vs. underclocking)
  • Are undervolting/underclocking proper english words anyway?
  • Follows a scheme of "from general to specific". The topic of the article is underclocking/undervolting. That it's for Pentium M processors is kind of secondary to that.

What do you think? I can do it if you agree.

Wyrfel 00:21, 21 Oct 2005 (CEST)


Good points. Personally I'm fond of short technical titles, but I agree about accessibility and consistency with the rest of the site. I have a feeling (though no proof) that the underclocking doesn't really work (as I noted recently), so how about "Reducing voltage on the Pentium M processor" for now?

BTW, "underclocking" is pretty standard techie jargon (and a clear parallel of the well-known "overclocking"). "Undervolting" is somewhat less common, though I've seen it in use.

--Thinker 00:55, 21 Oct 2005 (CEST)


Which patch to use?

Since I might find the time to fiddle around with reducing the power consumption further, I wonder which of the 3 alternatives works best. Any recommendations?

--spiney 11:05, 21 Dec 2005 (CET)


They all work... I think Alternative 2 is easiest to use.

--Thinker 13:06, 21 Dec 2005 (CET)


Init Script

Hi. I'm the author of the SysFS patch of "Alternative 2"

I have recently seen that someone has added your init script to my wiki page on gentoo-wiki. But unfortunatly this guy has removed all the exisiting content of the page at the same time. So a few hours later an admin of the site as reverted the page to its previous state.

Well that was just for the story of how I came to your wiki page. I just wanted to say That I have adedd again the init script to my page. It's a nice thing. A lot more "gentoo spirit" that what I was using before (that is adding some code in /etc/conf.d/local.start)

I have made some modifications to the init script before adding it on my wiki page. So maybe you want to have a look at it.

Cheers! --Bdz 23:26, 10 Jan 2006 (CET)


Trouble loading modules

If you receive the error after applying the bdz patch:

    FATAL: Error inserting speedstep_centrino
   (/lib/modules/2.6.15.4/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device

be sure you have included "ACPI tables" for decoding valid frequency - voltage pairs.

Also, note you may have to manually "modprobe" the speedstep-centrino during your boot sequence. For some reason it won't autodetect on my debian sid system.

Underclocking results in a *noticably* cooler processor, approximately 3-5 degrees, which is often enough to have the fan stop (now 43 deg basal temp on my lap.) The battery life boost is much more modest, I'm down to 17.5 W/h now with everything off.

--gsmenden 23:50, 12 Feb 2006 (EST)