Frequency Scaling

[deno]

Hi there,

I have p4 550 3.4 GHz and it's normal wokring temerature is about 60 C. I thought if I decrease frequency less power will be consumed and heat output will decrease.
But now it seems that there is no change regarding those things. Working temp is still about 60 C and 'idle' frequency in % above 10 % on both CPU (one is virtual of course - HT).

My question is, does it actually make any sense for one who runs X, Kde, etc. to use something like frequency scaling, because instead of 3% of CPU activity with normal 3.4 GHz i have approximately 15% - 40%CPU usage with 850 MHz.

d3n@mxhost ~ $ cpufreq-info
cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
driver: p4-clockmod
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 425 MHz - 3.40 GHz
available frequency steps: 425 MHz, 850 MHz, 1.28 GHz, 1.70 GHz, 2.13 GHz, 2.55 GHz, 2.98 GHz, 3.40 GHz
available cpufreq governors: ondemand, powersave, userspace
current policy: frequency should be within 850 MHz and 3.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 850 MHz.
analyzing CPU 1:
driver: p4-clockmod
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 425 MHz - 3.40 GHz
available frequency steps: 425 MHz, 850 MHz, 1.28 GHz, 1.70 GHz, 2.13 GHz, 2.55 GHz, 2.98 GHz, 3.40 GHz
available cpufreq governors: ondemand, powersave, userspace
current policy: frequency should be within 850 MHz and 3.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 850 MHz.

[rmh3093]

with a P4 all your have to your disposal is Intel Speedstep, ACPI P-States, and P4 Clock Mod.... all of these mechanisms reduce the clock frequency only... you wont see much power saving or heat change from using any of these because the cpu voltage always stays the same.... if you had a centrino or new cpu then you could use Enhanced speedstep which actually changes the voltage
_________________
Do not meddle in the affairs of wizards, for they are subtle and quick to anger.

[deno]

Thanks for a quick reply. So there is actually no use of such thing for me...

[rmh3093]

not exactly, i mean scaling down the frequency does reduce the amount of current drawn at a time which does reduce your heat and improve battery life, but not nearly as much as reducing the voltage in addition to the frequency
_________________
Do not meddle in the affairs of wizards, for they are subtle and quick to anger.