Re: [RFC][PATCH 12/12] PM / r8169: Add simplified run-time PMsupport

[Pavel Machek]

> > > Using /proc/acpi/battery/BAT1/state I measured the energy drawn in 10 minutes
> > > both with the network adapter in D0 and D3hot.  The results were that with the
> > > network adapter in D0 the box drew 2476 mWh, while with the network adapter in
> > > D3hot it drew 2361 mWh.  The difference is 115 mWh, or about 5% on this
> > > particular box.
> > > 
> > > This means about 0.1 Wh in 10 minutes, so we can save about 0.6 Wh per hour.
> > 
> > Which means it saves 0.6W :-). Measuring power in Wh/h is "interesting".
> 
> You can't save power, you can only save energy.  Wh is just an energy unit.

Of course we can save power, you just did :-).

(And in some cases -- data centers, limited cooling -- you are limited
by power, not energy. You are right that on notebooks, energy is more
important.)


									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/