On 7/16/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
First, I noticed that my CPU consumes considerably more
power (an extra 0.5W) when running at the lowest speed
(1.00GHz) as opposed to when it runs at its native speed
(2.16GHz); it may be a hardware flaw (ACPI?) or anything
else, I don't know.

What driver do you use to modify the clock?
If its clock-modulation, its not good for power consumption (only for
thermal emergency), afaik.

I wonder
whether cpufreq, in as cool and sexy as it is, does make any
sense at all (given the fact that it does introduce some
overhead). For me, it seems that it doesn't (even when I
adjust the minimum frequency so as to avoid the 1.00GHz
thing described above). My guess here is that a faster clock
allows the CPU to do its work quickly, and then sleep
longer. I may be wrong, and I would like to know whether
other people experience the same situation.

Try the ondemand governor. It should make the CPU go max speed, do the
work fast, then go back to low-speed&sleep state.
The cpuidle patch should also help make better use of C-states.

An idle kernel, for me,
produces (still in runlevel 1) just ~1 wakeup/second (with
C3 residency times of ~850-1000ms).

That should be good enough ;)


The next steps will be to identify userspace code that

Try some other hardware tweaks, such as backlight, tv-out-disable, etc.

--Edwin
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