We have a lab of 60 Sunblade 2500's which by university policy need to
live without A/C at night. We really would like to leave them up at
night to support remote logins, and hoped we could use power management
to reduce power enough to allow this.

We measured the power used by a 2500 and going from minimal power
savings to standard takes it from 200 watts to 100 watts. Still thats
6000 watts.

Is there any way to get further power reduction say be shutting off a
cpu or decreasing the speed (is that even possible?

> Is there any way to get further power reduction say be shutting off a
> cpu or decreasing the speed (is that even possible?

Turn 50 off and leave 10 running for late night loggins.

In article <e711ha$l09$1@finch.mathcs.emory.edu>, Ken Mandelberg <km@mathcs.emory.edu> wrote:
>We have a lab of 60 Sunblade 2500's which by university policy need to
>live without A/C at night. We really would like to leave them up at
>night to support remote logins, and hoped we could use power management
>to reduce power enough to allow this.
>

The SB2500 has a lot of PM stuff.
Mine used to power back so much that both CPU fans
would go idle, eventually. Plus disks, CD's and even
graphics cards can go idle (might have to be in
the right slot, though).

I'm not sure how much this saved though.

You might want to adjust the times for these components
to be a lot quicker. I believe some take hours to timeout.
I used something called apm_util, if I recall, from the command line.
Not sure if that's generally available, though. It might be an
optional package, or a diagnostic ....

Even better, if you could swap settings with a cron job between
day and night. Then it would go back to sleep a lot quicker
after a remote login at night. But it would still use less annoying
settings during the day.


Theres also the powersave/restore stuff to fully shutdown,
and restart quickly, but I don't know if it can be awakened
from the net. Probably not ...




>We measured the power used by a 2500 and going from minimal power
>savings to standard takes it from 200 watts to 100 watts. Still thats
>6000 watts.
>
>Is there any way to get further power reduction say be shutting off a
>cpu or decreasing the speed (is that even possible?