On May 30, 2008, at 16:07, Guntsche Michael wrote:
>
> I am most interested in keeping the temperature of my CPU down,
> which means slower fans, which means less noise.
> The main "problem" I have is that I do not know if this is a simple
> display issue or if I am having a more fundamental problem here.
Just FYI I found out the cause of my problem.
Reverting http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ed9cbcd40004904dbe61ccc16d6106a7de38c998
this patch resultsin the correct numbers for me.
<cpuinfo snip>
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 1
model name : Intel(R) Pentium(R) 4 CPU 1.70GHz
stepping : 2
cpu MHz : 637.500
<snip>
This patch was reverted because other people seem to have problems
with it, reverting the revert does not look like a good idea either.
But since I know now, that this is just a "display" problem and
everything is working otherwise, I'll just patch this locally for my
machine here.
Kind regards,
Michael
On Sun, 1 Jun 2008 23:57:14 +0200
Guntsche Michael <[email protected]> wrote:
>
> On May 30, 2008, at 16:07, Guntsche Michael wrote:
>
> >
> > I am most interested in keeping the temperature of my CPU down,
> > which means slower fans, which means less noise.
> > The main "problem" I have is that I do not know if this is a
> > simple display issue or if I am having a more fundamental problem
> > here.
>
> Just FYI I found out the cause of my problem.
>
> Reverting
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ed9cbcd40004904dbe61ccc16d6106a7de38c998
> this patch resultsin the correct numbers for me.
>
> <cpuinfo snip>
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 15
> model : 1
> model name : Intel(R) Pentium(R) 4 CPU 1.70GHz
> stepping : 2
> cpu MHz : 637.500
> <snip>
>
> This patch was reverted because other people seem to have problems
> with it, reverting the revert does not look like a good idea either.
> But since I know now, that this is just a "display" problem and
> everything is working otherwise, I'll just patch this locally for my
> machine here.
>
just as a side note.. you do realize that with p4-clockmod, your cpu is
still running at 1.7 GHz right? (it's just doing less work '-)
Arjan van de Ven wrote:
> On Sun, 1 Jun 2008 23:57:14 +0200
> Guntsche Michael <[email protected]> wrote:
>
>> On May 30, 2008, at 16:07, Guntsche Michael wrote:
>>
>>> I am most interested in keeping the temperature of my CPU down,
>>> which means slower fans, which means less noise.
>>> The main "problem" I have is that I do not know if this is a
>>> simple display issue or if I am having a more fundamental problem
>>> here.
>> Just FYI I found out the cause of my problem.
>>
>> Reverting
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ed9cbcd40004904dbe61ccc16d6106a7de38c998
>> this patch resultsin the correct numbers for me.
>>
>> <cpuinfo snip>
>> processor : 0
>> vendor_id : GenuineIntel
>> cpu family : 15
>> model : 1
>> model name : Intel(R) Pentium(R) 4 CPU 1.70GHz
>> stepping : 2
>> cpu MHz : 637.500
>> <snip>
>>
>> This patch was reverted because other people seem to have problems
>> with it, reverting the revert does not look like a good idea either.
>> But since I know now, that this is just a "display" problem and
>> everything is working otherwise, I'll just patch this locally for my
>> machine here.
>>
>
> just as a side note.. you do realize that with p4-clockmod, your cpu is
> still running at 1.7 GHz right? (it's just doing less work '-)
From my testing, I believe the only thing that p4-clockmod does is forces an
idle call when it could otherwise do work on an active process, so fullspeed and
idle uses *EXACTLY* the same amount of power as p4-clockmod slower speed and
idle (and therefore generates exactly the same amount of heat), the only power
difference would be that if you were using p4-clockmod to slow down the cpu when
it had an active running process (force the cpu to be idle a lot of the time
even though it has work). Arjan's point is that if you are using p4-clockmod
to slow down an idle cpu in hopes of saving power when the cpu is not being
used, then it is not going to make *ANY* difference in the power usage at all.
I tried it on my p4 here, and cannot see any power difference in idle/fullspeed
and idle/slowspeed, this is unlike the later power saving stuff that actually
does slow down the cpu frequency, and you can measure a different amount of
power usage with the different clock speeds and an idle cpu.
Roger
On Sun, 01 Jun 2008 21:36:58 -0500, Roger Heflin <[email protected]>
wrote:
> Arjan van de Ven wrote:
>>
>> just as a side note.. you do realize that with p4-clockmod, your cpu is
>> still running at 1.7 GHz right? (it's just doing less work '-)
> From my testing, I believe the only thing that p4-clockmod does is
forces
> an
> idle call when it could otherwise do work on an active process, so
> fullspeed and
> idle uses *EXACTLY* the same amount of power as p4-clockmod slower speed
<snip>
Thanks for the detailed information everyone. The first time I tested this
I was under the impression that it indeed had an influence on the produced
heat of the CPU. I did a quick test this morning and of course you are
right, there is no change at all.
This is a good thing though, since it gives me an excuse to upgrade this
machine to a C2D. :)
For the time being I will just disable the cpufreq stuff since it really
does not make a difference in my case.
Kind regards,
Michael
On Sun, 01 Jun 2008, Roger Heflin wrote:
> From my testing, I believe the only thing that p4-clockmod does is forces
> an idle call when it could otherwise do work on an active process, so
> fullspeed and idle uses *EXACTLY* the same amount of power as p4-clockmod
> slower speed and idle (and therefore generates exactly the same amount of
> heat), the only power difference would be that if you were using
> p4-clockmod to slow down the cpu when it had an active running process
> (force the cpu to be idle a lot of the time even though it has work).
Indeed. And if we had a generic interface for throttling (ACPI
T-states-like) and frequency changes (ACPI P-states-like), we could just
move p4-clockmod to the throttling one (and NOT letting it register with
the frequency changes interface), and be done with it.
Do we have these interfaces?
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
On Mon, Jun 02, 2008 at 12:37:59PM -0300, Henrique de Moraes Holschuh wrote:
> Indeed. And if we had a generic interface for throttling (ACPI
> T-states-like) and frequency changes (ACPI P-states-like), we could just
> move p4-clockmod to the throttling one (and NOT letting it register with
> the frequency changes interface), and be done with it.
>
> Do we have these interfaces?
No.
--
Matthew Garrett | [email protected]