[ltp] question about cpu-speed settings (TP240)

Tino Keitel linux-thinkpad@linux-thinkpad.org
Mon, 2 Aug 2004 13:21:02 +0200


On Sun, Aug 01, 2004 at 21:55:40 +0000, Sascha Heid wrote:
> Hi all!
> 
> I have a thinkpad 240 (300MHz) and it has the following BIOS-settings
> for the cpu-speed in battery mode:
> 
> fixed max (100%=300MHz)
> fixed medium (75%=225MHz)
> fixed slow (50%=150MHz)
> auto medium
> auto slow
> 
> The last 2 are which i dont understand what they are doing.
> When im looking for the cpu-speed with "cat /proc/cpuinfo" i get 225MHz
> for auto medium and 150MHz for auto slow, no matter if the cpu is pretty
> idle or under load for a longer time.

Maybe the Linux kernel isn't notified about the changes of the CPU
speed in the auto modes. Then the frequency at boot time will always be
displayed.

> 
> Does anyone know what these settings do?

I think they use 225 or 150 MHz if the CPU is idle and switch to
higher CPU clock speeds if there is some CPU load.

Regards,
Tino