Hi,
I have an HP/Compaq nx7000 centrino 1.5GHz running mdk with the 2.6.0-1mdk rpm kernel. When I boot my machine when plugged into the mains the output from dmesg states:

calibrating APIC timer ...
..... CPU clock speed is 1495 MHz.

Howver, when I boot up when running on batteries:
calibrating APIC timer ...
..... CPU clock speed is 597.0951 MHz.

Needless to say when running on mains the machine is a lot quicker. My /proc/acpi/processor/CPU0/throttling file contains the following:

state count: 8
active state: T0
states:
*T0: 00%
T1: 12%
T2: 25%
T3: 37%
T4: 50%
T5: 62%
T6: 75%
T7: 87%

I have tried changing to the other states but the default T0 state is the quickest and when running on batteries this is 597MHz.
How can I ensure that the processor is calibrated as 1495MHz when I am running on batteries.
Cheers,
Sat

PS Does anyone know what's happened to www.x1000forums.com?

Hi,
I'm compiling kernel 2.6.1, and there's an option for Intel Centrino SpeedStep To activate (not activated by default).
I guess this is the part to dynamically change the CPU freq. Centrino automatically switch to 600 MHz when on batteries to save power. However, it should increase its frequency dynamically when needed (If you ask a lot from your CPU).

So I guess no worries for now, just check if the speed increases when you're demanding power.

'hope that helps !

Tanguy

Thanks for replying, but when I am running under high cpu load the frequency does not dynamically change, the fan never comes on. I believe this is because when on batteries the maximum clockspeed is 500 MHz.
Cheers,
Sat

The speedstep-centrino module only allows control of the processor clock speed on the fly, it doesn't actually manage it on it's own. I use cpudyn to do this on my laptop. Cpudyn runs the processor at it's minimum until you need more power, at which point it immediately clocks up. I did some tests and have been using it for quite awhile now and have yet to notice any speed difference, though i can get roughly another 40% battery life.