Arch Linux

sikke

Member

From: Finland

Registered: 2009-02-02

Posts: 7

Intel Atom Speedstep/cpufreq

Hi!

Can anyone tell me if Speedstepping should work with Arch and Intel Atom? I've got an Intel Atom based system but I've had no luck with cpufreq.

Modprobing the modules give me errors like this

FATAL: Error inserting acpi_cpufreq (/lib/modules/2.6.28-ARCH/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko): No such device

I've been trying to follow how to's like this http://wiki.archlinux.org/index.php/Cpufreq

Thanks in advance!

rebugger

Member

From: Germany

Registered: 2007-10-28

Posts: 229

Re: Intel Atom Speedstep/cpufreq

Depends on what atom you have. the n270 supports speedstepping - but the best is, to use the ondemand govenor and let the cpu scale itself.

ckristi

Member

From: Bucharest, Romania

Registered: 2006-11-21

Posts: 225

Re: Intel Atom Speedstep/cpufreq

Try modprobing acpi_cpufreq twice. I remember at some point this solved my problem with this error.

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In love I believe and in Linux I trust

sikke

Member

From: Finland

Registered: 2009-02-02

Posts: 7

Re: Intel Atom Speedstep/cpufreq

It's Atom 330 and after that being said I can do a little Google search and find out that it doesn't support Speedstep. Silly me...
Is it possible to use cpu frequency scaling with it even though it doesn't support Speedstep?

rebugger

Member

From: Germany

Registered: 2007-10-28

Posts: 229

Re: Intel Atom Speedstep/cpufreq

Sorry, for answering so many days later, but the answer is: no - it is not possible. But forget speedstepping the atom uses so less power that it doesnt matter

Bfg

Member

From: Italy

Registered: 2004-04-03

Posts: 15

Re: Intel Atom Speedstep/cpufreq

it seems to me that actually atom 330 supports only "powersave" mode which lower cpu frequency at 200 MHz (more or less a router's speed) or "userspace" mode so you can fix manually the frequency in a range (200 MHz, 400 MHz, 600 MHz, 800 MHz, 1000 MHz, 1.20 GHz, 1.40 GHz, 1.60 GHz).
the modules are: p4-clockmod cpufreq_powersave cpufreq_userspace

harbind

Member

Registered: 2009-05-08

Posts: 22

Re: Intel Atom Speedstep/cpufreq

So there is lots of different frequencies but I can't change those on demand? Sounds strange to me...

Gusar

Member

Registered: 2009-08-25

Posts: 3,605

Re: Intel Atom Speedstep/cpufreq

p4-clockmod doesn't actually do freq scaling, it does what the module says - modulation. Which is a whole different thing that doesn't actually bring any benefits. I've had a nice link where all this was explained, but I can't seem to find it now...

Edit: Found it - http://www.codemonkey.org.uk/2009/01/18 … 4clockmod/

Last edited by Gusar (2010-04-22 20:41:17)