I recently bought a laptop with centrino technology that comes with a
pentium M 2GHZ.

I used to have a laptop with an Athlon XP, 2000+ and when setting the
cpufreq to powersave (on the klaptop applet) the fans would almost not
turn on.

The same does not happen with my new processor. When I set it to
"powersave" and the processor speed drops down to 800 MGHZ, the fans are
still on for most of the time. Even if I'm just browsing!!

I also get this odd message when I'm turning off my computer; "Unloading
cpufreq modules: FAILED". But I must say that the modules are loaded.

Does anyone have any experience with pentium M processors? Do you have a
similar behaviour?

Maybe it is just normal, but when I on Windows the processor is much
quieter...

I realise I'm being quite vague but I can provide any details you need to
help me.

Any comments/suggestions will be most welcome.

Thanks a lot in advance,

nelsonnery

I see that this is not a popular subject :-(

Let me ask then a different question.

How does this cpufreq thing works?

I know I need some daemon (like cpufred, powernowd, ...).

Which one would you recommend?

I am sure that there is someone out there with a Pentium M running on Linux...
I would like to know which behaviour do you have on your machine.

Thanks for all the comments and help.

nelsonnery

Hey,

I'm running Slackware on Pentium-M machine and also experiencing some
problems obviously connected with ACPI. But yesterday I managed to do
a little step, that is inserting a 'processor' module. Try it, after that my fan
slowed down immediately.
I'm still googling for further responses to my questions (can not check the
temperature or change the cpu frequency on demand...) If you happened to
find anything out since one month ago, please write it here. Good luck!

I also found a nice site, it may help us both:
http://web.ics.purdue.edu/~nino/Linux/cpudyn.html

I have also a Pentium M, but my fan is nearly never running. I didn't take much attension to power management and so on. I have acpi, and I get the message "acpi-cpufreq: CPU0 - ACPI performance management activated", when I boot. I also have the modules battery, button and ac, which seem to be related with acpi and the scripts acpid, cpuspeed and lm_sensors in /etc/init.d, which are executed on boot-up. When I take a look on the running processes, I can see, that acpid, lm_sensors and cpuspeed are running. But I have to admit, that I never checked, if it's working correctly, but at least I don't get any error messages.

Are you able to check your system's temperature? Or the current FAN speed?
They should be available under the /proc system (/proc/acpi/thermal_zone and /proc/acpi/fan). Even after loading "thermal", "processor" and "fan" modules I cannot check current values because have these directories empty... Have you got any idea what might be the problem? Thanks!

No, I can't read neither the temperature nor the fan speed, but maybe it isn't necessary to have this to be able to manage the fan speed correctly.

But I have the files info, limit, power and throttling in /proc/acpi/processor/CPU0/. My entries in info are:

processor id: 0
acpi id: 0
bus mastering control: yes
power management: yes
throttling control: yes
limit interface: yes

On http://acpi.sourceforge.net/document...processor.html I found some information about changing the states of the processor.

Hi.

I think that part of my problem is that the minimum frequency I can get to in Windows is 600MHZ whereas in Linux is 800MHZ. Does anyone know how can I override the information Linux has about my processor so that I can lower the frequency down to 600MHZ?

Thanks.

nelsonnery

There is a file somewhere under /sys/devices/system/cpu/.../ called scalling_minfreq or something similar. I don't
remember now. Try to "echo" a correct value to that file. I have never tried that however but believe it might help.

Hi.

The file you refer is "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq"

I have

"# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq
800000"

and this seems to be unchangeable because I have
"# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
2000000 (...some other ones... and ) 800000"

When I do
# echo "600000" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq

the shell that I'm using just hangs...

I start to think that what I need to change is the file
"cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies"

But using "echo" I get the same problem :-(

Any ideas?

Thanks for all the help.

nelsonnery

Hello,

You're right, the "echo" trick doesn't work, my shell doesn't hang however...
But I think your problem lies somewhere else.. I also have the min_freq set as
800MHz (AFAIR in windoze it's 600) and my fans are off most of the time until I
start doing something really hard...
I'm running cpuspeed -d everytime I launch the system. This daemon sets the
frequency according to the load, but it certainly needs some modules inserted,
don't remember exactly. Try to run it, it might help.

But for me it's not enough anyway. After a few minutes of hard working my laptop
shuts down (and it's not a system shutdown, I believe it's initiated by some kind
of thermal-alert procedures...) I have completely no idea what to do, somehow it's
impossible to check temperatures and fans' speeds I'm pretty sure that it's
hardware issue - after rebooting to windoze the problem remains. Maybe someone
has a similar problem..? I would be glad if there were any possibility to work
it around by some software tricks until I get angry enough to have it repaired ;-)


Cheers!

heya,
i find a good thing to do it to try use the 'ondemand' governor when running on batteries or AC. It then will clock the CPU at the lowest frequency when idle and bump it up to the full speed when you put a load on the CPU.
If you have all the governors compiled into your kernel or ready as modules you can try type #
to activate ondemand.
You can set the TRIP POINTS for when the fan kicks in as well... This way you can set it up so the trip point is at a higher temperature than when your machine is idle....
Check out this thread, has heaps of info
http://www.linuxquestions.org/questi...your+pentium+m

also i your are using ACPI you can check temp with:
# cat /proc/acpi/thermal_zone/THRM/temperature