Re: problem with cpu eating too much power, prize given if solved

Keld Jørn Simonsen
2004-06-29T22:50:08Z

On Wed, Jun 30, 2004 at 12:10:19AM +0200, Pavel Machek wrote:
> Hi!
>
> > > > Many times I just want to read the screen, eg emails or documents,
> > > > and then still the cpu will be in idle mode, where
> > > > it uses 7.5 W out of the about 15 W that the whole machine uses.
> > > > I have found out from Intel data sheets that my
> > > > Mobile Intel Celeron 2.0 GHz CPU consumes 7.5 W in idle loop/
> > > > stop grant/sleep states, (and 5.0 W i deep sleep state).
> > > >
> > > > So I would like to have the CPU stopped completely (consuming 0 W)
> > > > while I still could read the screen. In that way I should
> > > > be able to have about double the lifetime on the battery,
> > > > going to about 7 hours from the 3.5 hours I have now.
> > > >
> > > > I would like the machine to wake up again by any keystroke
> > > > on the keyboard or mouse input. I would like the input to be
> > > > reacted upon (not just used to wake up the system, and
> > > > then forgotten).
> > > >
> > >
> > > S1 is what you want... but... if you get what you asked for,
> > > do you realize that for example clock would not update on the desktop
> > > in this mode?
> >
> > Maybe S1 is what could do this. I understand that I could not then have
> > the clock updated every second but every minute would work, and even if
> > the screen was not updated every minute it would be fine. But I would
> > expect the clock to be accurate when the cpu is started again.
>
> Can you verify that your hardware can do S1? (cat /proc/acpi/sleep).

It says:
S0 S3 S4 S5

/sys/power/state says:

standby mem disk

Best regards
keld