# changing CPU frequency

## [n00b@localhost]

Following the gentoo power management guide I can't get the cpu frequency to change. The machine is an IBM Thinkpad T22 with a 900MHz Speedstep-capable Pentium 3.

At the point where it says to go to /sys/devices/system/cpu/cpu0/cpufreq/ I get stuck. There is no cpufreq directory in cpu0 and I cant find anything in the troubleshooting of any help. The closest thing is the first bit which suggests making sure your processor supports frequency scaling and that you are using the correct cpufreq driver.

```
dmesg | grep CPU | tail

...

ACPI: Processor [CPU] (supports C1 C2 C3)

ACPI: Processor [CPU] (supports 8 throttling states)

```

So I reckon it supports scaling (does under win98 anyways). I'm using the "Intel Speedstep on 440BX/ZX/MX chipsets (SMI interface)" driver from the kernel (is this the right one?) and have activated the extra modules as per the guide.

The rest of the guide works fine (Hard Disk spindown, LCD poweroff, ACPI events are a bit iffy) so how do I change the speed of my CPU?

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## moocha

 *[n00b@localhost] wrote:*   

> At the point where it says to go to /sys/devices/system/cpu/cpu0/cpufreq/ I get stuck. There is no cpufreq directory in cpu0 and I cant find anything in the troubleshooting of any help.

 

Did you compile the kernel with CPUFreq support and with the IBM Thinkpad extras ACPI support?

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## [n00b@localhost]

In the guide it says to enable CPUFreq support, so I did. I also enabled the IBM extras.

I also just noticed I had SMP enabled so I disabled it and compiled a new kernel. Still doesn't work right though.

Thanks for the suggestions.

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## moocha

Hm... Can't think of anything else right now. Perhaps you could try a different kernel version or source tree?

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## Defiance

I'm not sure but maybe check to see if you had the governors included as well?

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## [n00b@localhost]

All the governors are compiled in, and the userspace one is set as the default.

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## scottfk

If you have the speedstep stuff compiled into the kernel (not as a module), try booting with argument "speedstep-lib.relaxed_check=1" to see if that gets you going.

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## voytas

same problem here with pentium3 700MHz

none of the cpufreq modules loads, even with relaxed_check=1...

in winxp speedstep is working fine...

EDIT:

this worked for me: https://forums.gentoo.org/viewtopic-p-3216904.html#3216904

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