Comments on: Saving Power with CPU Frequency Scaling

By: Fresh From FriendFeed | Young David

Fresh From FriendFeed | Young David — Thu, 12 Mar 2009 22:07:06 +0000

[...] “Saving Power with CPU Frequency Scaling” ( http://tinyurl.com/dfqt9m )Nabble – Xen – User – Xen backups using LVM Snapshots Powered by Fresh [...]

By: Samba

Samba — Tue, 03 Mar 2009 18:45:14 +0000

Hi
I have all the drivers but anyone works

root@samba:/sys/devices/system/cpu/cpu0# ls /lib/modules/`uname -r`/kernel/arch/*/kernel/cpu/cpufreq
acpi-cpufreq.ko gx-suspmod.ko longrun.ko powernow-k6.ko powernow-k8.ko speedstep-ich.ko speedstep-smi.ko
cpufreq-nforce2.ko longhaul.ko p4-clockmod.ko powernow-k7.ko speedstep-centrino.ko speedstep-lib.ko
root@samba:/sys/devices/system/cpu/cpu0# modprobe acpi-cpufreq
FATAL: Error inserting acpi_cpufreq (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe cpufreq-nforce2
FATAL: Error inserting cpufreq_nforce2 (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/cpufreq-nforce2.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe gx-suspmod
FATAL: Error inserting gx_suspmod (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/gx-suspmod.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe longhaul
FATAL: Error inserting longhaul (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/longhaul.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe longrun
FATAL: Error inserting longrun (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/longrun.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe powernow-k6
FATAL: Error inserting powernow_k6 (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/powernow-k6.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe powernow-k7
FATAL: Error inserting powernow_k7 (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/powernow-k7.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe powernow-k8
FATAL: Error inserting powernow_k8 (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/powernow-k8.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0# modprobe speedstep-centrino
FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.27-11-generic/kernel/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device
root@samba:/sys/devices/system/cpu/cpu0#

I have an Intel Celeron M

root@samba:/sys/devices/system/cpu/cpu0# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Celeron(R) M CPU 520 @ 1.60GHz
stepping : 6
cpu MHz : 1595.962
cache size : 1024 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx lm constant_tsc up arch_perfmon pebs bts pni monitor ds_cpl tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 3191.92
clflush size : 64
power management:

Please help!!!!!!!!!!!!!!!!!!!!!!!!!!

Thank you in advance

By: Drew

Drew — Wed, 02 Apr 2008 04:46:36 +0000

Efficiency is defined differently depending on what you’re doing.

An efficiency of a CPU could be defined as how much energy is used in calculations (while anything that’s ‘wasted’ is heat).

This means that if your computer is contributing to heating your home, there is no waste (at least between the outlet and the computer), and you’re basically at 100% efficiency (if you consider the heat as useful work).

Even a high efficiency furnace, if it depends on combustion of natural gas or propane, will still allow some heat to escape out the flue in the exhaust. And an electric furnace doesn’t perform any binary calculations. :)

By: Otto Zelada

Otto Zelada — Sat, 18 Aug 2007 08:22:08 +0000

Try modprobe p4-clockmod, that worked for me.

By: Ashrentum

Ashrentum — Thu, 05 Jul 2007 17:36:51 +0000

I have the same problem that #9 Muskatnuss Being root I can’t write in scaling_max_freq. Even rebooting the system with the /etc/sysfs.conf modified, I get the same response, 800000 as the max freq possible. I’ll try to solve the problem.

Anyway, thanks for this great tutorial

By: Muskatnuss

Muskatnuss — Tue, 22 May 2007 21:48:46 +0000

Hey
Got an amd 64 x2 Tl-52 Processor 2cores 1.6 GHZ!
I followed your tutorial striaght ahead but the only thing i got working is setting ondemand as default governor!

but whenever i try to change ’scaling_max_freq’ in 1600000 it does nothing…
when i do a cat it says 800000 ?!?!

Also the Boot string that should change it on startup doesn´t work… but it works on the governor without any problem.

so how do i get my cpu getting full speed ???
ty for any help
greeetz Muskatnuss

By: Anonymous

Anonymous — Mon, 26 Feb 2007 13:44:56 +0000

i have problem like this

FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.17-11-generic/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device

i have intel core duo T2050 with speedstep

what’s wrocng?

By: Bert Beals

Bert Beals — Tue, 20 Feb 2007 20:55:55 +0000

I can’t find a driver. I’m running RHEL 4u4 AS on a dual socket quad-core Intel box. I don’t have any directories below :
/lib/modules/`uname -r`/kernel/arch/*/kernel/

I see nothing below /sys/devices/system/cpu/cpu#.

I do see the on demand governors, cpufreq_powersave and cpufreq_ondemand and can modprobe them.

What am I missing?

Thanks.

By: João Laureano Leme

João Laureano Leme — Wed, 10 Jan 2007 21:28:49 +0000

Thanks a lot for the tips…
Finally I have CPU freq scaling turned.

By: Alvin Sun

Alvin Sun — Wed, 13 Dec 2006 20:53:22 +0000

Thanks for this very nice tutorial
Do you have any idea, how can I write a c program to adjust cpu frequency during the run time, such as which functions I can use and so on?