HOWTO: CPU Frequency Scaling w/ Kernel Module

[HAARP]

I believe a lot of you are having problems because the bios does not have a processor state table available. If that is the case, then the kernel modules will not work.

Yup. That's exactly it.

1) Try to get an updated bios with support with ptable support for your cpu.

No can do, my BIOS isn't being maintained anymore. Too old.

2) Recompiling the kernel as suggested by others. Look at the following links.

Wouldn't a kernel module suffice?

[Rollerbob]

This may help some people. I'm running an Athlon 64 X2 dual core machine and finally got Cool 'n' Quiet working (not sure about the 'Quiet' bit but that's probably because of my cheapo PSU!)

I installed the K8 SMP kernel using Synaptic and followed the instructions in this howto. However I, like others, got the following error:

# modprobe powernow-k8
FATAL: Error inserting powernow_k8 (/lib/modules/2.6.15-26-k7/kernel/arch/i386/kernel/cpu/cpufreq/powernow-k8.ko): No such device 

I was pretty sure that I had enabled the Cool'n'Quiet in the BIOS of my motherboard (ASUS A8V-VM). However, being a bit of a noob, I had only enabled 'Power Management' thinking this was the name for Cool'n'Quiet.

After rooting around in the BIOS interface, I found the real Cool'n'Quiet option, so I enabled it and this solved all the problems.

Incidentally, because I have two CPUs, I have a line for each in my /etc/sysfs.conf. I assume this is correct.

devices/system/cpu/cpu0/cpufreq/scaling_governor=ondemand
devices/system/cpu/cpu1/cpufreq/scaling_governor=ondemand 

[igsimon]

I have Ondemad set up per this HOW TO. It works when I first boot up switching frequencies fine. After a short time it seems to stick at the highest frequency setting when I do not seem to have any load. I have AMD64 X2 processor.

[igsimon]

ondemand is working fine - turnsout BEAGLED somehow is getting in a state that it uses 100% of cpu for long periods of time

[Nabor]

Why is this entry of all modules in /ets/modules necessary?

I know, it's necessary because without this entries the powersaved doesn't work during system startup (edgy) but it works when restarting it manualy...

I want to understand that... what is the difference?

Because the modules will be loaded in both cases otherwise a manualy restart auf powersaved would also fail or not?

Nabor

[linuxguiri]

Just as an FYI, in Edgy Eft ondemand will be automatically loaded in favor of powernowd by the powernowd startup script, if your CPU can use ondemand without choking (SpeedSteps and other older-generation CPU's had considerable delays on frequency switches, so they will be using powernowd instead)

Does this imply that either the speedstep or powernow module is also loaded?

I have a Core 2 Duo T5600 and I'm having trouble with the cpu freq being locked at maximum after resume from suspend.

I tried following this howto (removing powernowd and installing modules) but the max. cpufreq continued and it broke network manager after resume from suspend.

So then, I tried reinstalling powernowd and removing the modules, but I can't remove the speedstep-centrino or the cpufreq-ondemand modules because they are in use. Is this because powernowd is calling both of them?

[dutchmega]

I'm wondering if the voltage is also being lowered. I don't want to use Cool & Quiet because I have overclocked my CPU and when the voltage drops, it gets a bit unstable

[lazyd2]

I believe that in "Step 5" for Dual Core processors it should be

sudo -s
echo conservative > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo conservative > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

and again the same in /etc/sysfs.conf

devices/system/cpu/cpu0/cpufreq/scaling_governor=ondemand
devices/system/cpu/cpu1/cpufreq/scaling_governor=ondemand

Thanks for the how to=D>

[gotak]

I tired this and my cpu freq is stuck a 1 ghz what gives?

[Lomz]

Hi

thanks for a wonderfull howto, mi problem is that when I restart the computer it seems like it somehow doest remember this settings, and I need to run all the commands again.
And I am not using a live cd...

Anybody has an idea about how to solve this?