I have a centrino 715 (1500 Mhz) and I'm trying to use acpi speedstep feature.

I've included speedstep-centrino module and I'm using cpufreqd.

Cpufreqd seems to work if I look at /sys/devices/system/cpu/cpu0/cpufreq/??_cur_frequency or something similar.
I see the frequency changing according to my cpufreqd.conf options.

But if I look at
/proc/aci/processor/cpu0/performance
I can see the 2 possible states, P0 (1500 Mhz) and P1 (600 Mhz) but always 1500 Mhz is selected!!

Which of the two do I have to look at? Who is saying the truth?

If I do:
echo "-n 1" > performance
or
echo 1 > performance

the state does not change!
Also using KDE utilities I can't go nowhere, battery utility always stays on 1500 Mhz and System monitor always says me my notebook is running at 1500...

What do I have to trust?
/sys or /proc ??

Thanx

What is the contents of the file /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors and scaling_governor?

Eric

I have the same CPU but I'm running Fedora Core 4.

I have found two files that show the correct current CPU speed:

/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
/proc/cpuinfo

I don't have /proc/acpi/processor/cpu0/performance

The reason why I trust those two files is that they agree with each other and with the fan noise. I have observed (via the cpufreq-applet) that all the frequencies in /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies are used from time to time. But all of that only started to work when I uncommented all the options in cpuspeed.conf and most importantly used DRIVER="acpi-cpufreq". DRIVER="speedstep-centrino" did NOT work for me.

I'm not using cpufreqd. I believe that my version of either acpi or cpuspeed already does what cpufreqd used to do, but I am by no means an expert...

One other thing that did not work in the beginning is the power management mode switching (not sure if that's the correct term). My /proc/acpi/processor/CPU0/power always showed the usage for C3 to be 00000000. It should actually be the highest number of the three unless, of course, you run processor intensive tasks. That changed only when I unloaded my USB drivers (uhci_hcd and ehci_hcd). USB drivers seem to be notorious for obstructing power management features.