[Hampshire] Power reduction on a home "server"

Hi all,

I don't have physical access to the machine as it is my server at home, so
I can only report on stuff I can query via ssh :)

Given rising gas / elec prices, I am keen to reduce my power consumption
as much as possible. My old low power via eden server died, and I replaced
it with the cheapest thing I could buy at the time a "AMD Sempron(tm)
Processor LE-1100" (from /proc/cpuinfo).

I've realised that I have no idea if any cpu throttling is enabled, or
even how to do this for a server box. But give that all this does is serve
up a webmail client, IMAP for internal mail use, and simple SAMBA / NFS
file sharing, I'm sure it doesn't need to run full tilt!

Does anyone have any experience of underclocking AMD chips? Any references
would be great.

Also, how can I tell if cpu speed scaling etc. is actually working? I have
the following process running:

/usr/libexec/hald-addon-cpufreq

which kind of implies there is something going on there, but I'm at a loss
as to how to configure it, or find out if it is working / doing any
scaling at all.

All comments and suggestions welcome :)