Power management on older laptop.
This is an old Dell Inspiron 7500 with an Intel PIII - (Coppermine)
running debian 'lenny'.
The hardware supports an early version of the SpeedStep technology that
makes it possible to switch clocking between 650MHz and 500MHz. This is
normally done via a BIOS option where the focus appears to be on battery
life.
Since the batteries are long dead and will not be replaced, I'm more
looking into trying to lower the laptop's temperature a bit by having it
either throttle the CPU, or put to sleep whatever components are not
strictly necessary, when I'm not using the system.. or doing what I'm
doing now - interacting at a snail's pace with my mailer, trying to
sensibly describe my problem to debian-user.
Initially, when I tried linux, I figured that this laptop was just too
old and would not support any of the acpi stuff at all except perhaps
for the very basics, such a keeping track of the CPU's temperature, or
powering off the machine at the end of the shutdown procedure - which is
basically the two (useful) features that I have so far successfully been
using.
But then, prompted by a recent post on this list where s/o wanted to
control a noisy fan via software, I took another look at relevant files,
both in the /proc and /sys trees, and found stuff that looked promising,
initially at least - hinting at different "available" states, and
throttling capabilities in particular indicating I could clock the
processor down to as little as 12% of its native capability.
Unable to find any clear answers as to how I should go about doing that,
even after an extended "Google Advanced Search" session, I eventually
installed such packages as "cpudyn" and "cpufreqd" mainly hoping that
their documentation and playing with them a bit might help clarify.
I was unable to get these programs to do anything that I could see, the
system seems to be stuck in the "P0:T0" state and that's that..
As part of the "apt-get cpufreqd" .. debian even refused to start the
daemon, suggesting that the system is not properly configured - lsmod
indeed does not show that anything relative to these functionalities has
been loaded.
Is the system misconfigured, are the capabilities I'm looking into not
available for my hardware, and the /sys/ & /proc/ files I looked at mere
generic placeholders that have no meaning on my system?
I took a look at /lib/modules and tried to guess which module might be
the correct one from my particular hardware - and then decided it was
time to take a break.
Rather than waste more time speculating, I thought that maybe someone
who has been down this road already might be able to comment on
feasibilty with comparable hardware and possibly direct me to the
relevant manuals.
Thanks,
CJ
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