LinuxQuestions.org - How to control cpu stepping.

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How to control cpu stepping.

I have a Pentium M laptop and just noticed that it does not have a speedstep type thing. I tried watching a dvd and realized it was going way to slow because the cpu was probably at 600mhz and not 1400.

How do I manually instruct the system to make the processor full power?

Quote:

Code:

SYSCTLS

    hw.acpi.cpu.performance_speed

            Sets the speed of the CPU, if it supports multiple speeds, while

            in the performance power profile.



    hw.acpi.cpu.economy_speed

            Sets the speed of the CPU, if ...

This is from the ACPI manpage. You can view the current status of variables by typing "sysctl -a | grep acpi"

If you see the ones above (and you should if your processor supports them which yours does) you can change them.

Code:

sysctl hw.acpi.cpu.current_speed=xxx

Note: I am currently unable to discover what the documented values are for this sysctl or what they mean. If you could post what yours currently is... we might be able to guess and play around. Even better... I am going to look further on this issue -- you have been waiting long enough for any type of answer so this will do for the moment.

EDIT: sorry... this should have refered to .current_speed in the example above. And you can set it to the value in hw.acpi.cpu.performance_speed to get the max speed in from your system. Hope this helps.

Note: If these are read only on a running system... we can set the current speed in /boot/device.hints to tell it to use the faster speed on boot.

Quote:

Originally posted by frob23
Note: If these are read only on a running system... we can set the current speed in /boot/device.hints to tell it to use the faster speed on boot.

I believe at boot it says its running at 100%. But im sure it slows it down because watching a dvd is impossible without pluggin it in. The interesting is that when I plug the laptop in or unplug it a little message comes up and says "ACPI ECONOMY" or "ACPI PERFORMANCE".

Something like that.

Ill try to get you the outputs of those later today.

Thanks.