Talk:Pentium M undervolting and underclocking - Revision history

Maxus98: /* Voltage and frequency correlate */ new section

2010-01-25T20:49:27Z

‎Voltage and frequency correlate: new section

KotCzarny: fid:vid for a processor family is similiar

2007-11-17T03:18:43Z

fid:vid for a processor family is similiar

Hmh: VID-only tables are useless

2007-09-07T20:30:04Z

VID-only tables are useless

Zhenech at 13:45, 14 February 2007

2007-02-14T13:45:12Z

Gsmenden: Various speedstep-cetrino notes

2006-02-15T06:26:11Z

Various speedstep-cetrino notes

Gsmenden: /* Unrecognized processors */

2006-02-14T04:18:32Z

‎Unrecognized processors

Gsmenden: /* Unrecognized processors */

2006-02-14T03:26:17Z

‎Unrecognized processors

Gsmenden: /* Unrecognized processors */

2006-02-14T03:03:04Z

‎Unrecognized processors

Gsmenden: /* Init Script */

2006-02-13T05:09:15Z

‎Init Script

Bdz at 22:26, 10 January 2006

2006-01-10T22:26:55Z

← Older revision		Revision as of 20:49, 25 January 2010
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	--[[User:KotCzarny\|KotCzarny]] 03:16, 17 November 2007 (UTC)		--[[User:KotCzarny\|KotCzarny]] 03:16, 17 November 2007 (UTC)
		+
		+	== Voltage and frequency correlate ==
		+
		+	Transistors operate faster at higher voltages, allowing overclocking, and making it difficult to cool these cpu´s, as both higher voltage and frequency increase the heat loss. That is also true in the other direction:
		+	Lowering the frequency lets your cpu operate stable at lower voltages, but only lowering the voltage very likely makes it unstable. If it works anyway, fine, but be aware of the correlation of f_max and voltage. ~~Maxus

← Older revision		Revision as of 03:18, 17 November 2007
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	--[[User:Hmh\|hmh]] 20:30, 7 September 2007 (UTC)		--[[User:Hmh\|hmh]] 20:30, 7 September 2007 (UTC)
		+
		+	Observation: fid:vid for a processor family is similiar
		+	i have two machines with p-m dothan processor (x41t 1.5 ghz LV and x32 1.8ghz) and it seems that for any given frequency (FID), stable voltage (VID) is very similiar, if i get my hands on some banias based thinkpad, i will check if that theory extends there
		+
		+	--[[User:KotCzarny\|KotCzarny]] 03:16, 17 November 2007 (UTC)

← Older revision		Revision as of 20:30, 7 September 2007
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	--[[User:Zhenech\|Zhenech]] 14:45, 14 February 2007 (CET)		--[[User:Zhenech\|Zhenech]] 14:45, 14 February 2007 (CET)
		+
		+	== VID-only tables are useless ==
		+
		+	Please don't publish only VID data. You also need to publish the FID, because not all BIOSes/OS combinations allow one to select every possible frequency step, and users will later need to find out which FID correspond to each VID...
		+
		+	--[[User:Hmh\|hmh]] 20:30, 7 September 2007 (UTC)

← Older revision		Revision as of 13:45, 14 February 2007
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	--[[User:gsmenden\|gsmenden]] 23:50, 12 Feb 2006 (EST)		--[[User:gsmenden\|gsmenden]] 23:50, 12 Feb 2006 (EST)
		+
		+	== Undevolting a Core Duo ==
		+	I have a Core Duo T2500, according to https://www.dedigentoo.org/trac/linux-phc/wiki/IntelCoreLimitationsOfLinuxPHC0_2_X, undevolting does not work really good, but the info is quite old too. So I want to ask if somebody is running an undervolted Core-CPU and has success with longer battery life and lower fan usage?
		+
		+	--[[User:Zhenech\|Zhenech]] 14:45, 14 February 2007 (CET)

@@ 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:
       FATAL: Error inserting speedstep_centrino
      (/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)

← Older revision		Revision as of 03:26, 14 February 2006
Line 58:		Line 58:

	...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?		...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?
		+
		+	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.
		+
		+	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.)

	--[[User:gsmenden\|gsmenden]] 23:50, 12 Feb 2006 (EST)		--[[User:gsmenden\|gsmenden]] 23:50, 12 Feb 2006 (EST)

← Older revision		Revision as of 05:09, 13 February 2006
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	----		----
		+	== Unrecognized processors ==
		+	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 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
		+	(/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 speedstep-centrino load for you without difficulty?
		+
		+	--[[User:gsmenden\|gsmenden]] 23:50, 12 Feb 2006 (EST)

← Older revision		Revision as of 22:26, 10 January 2006
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	--[[User:Thinker\|Thinker]] 13:06, 21 Dec 2005 (CET)		--[[User:Thinker\|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!
		+	--[[User:Bdz\|Bdz]] 23:26, 10 Jan 2006 (CET)
		+
	----		----