Re: Power consumption HZ100, HZ250, HZ1000: new numbers

Stephen Clark
2005-08-02T13:11:28Z

James Bruce wrote:

>Theodore Ts'o wrote:
> > On Mon, Aug 01, 2005 at 12:18:18PM -0400, James Bruce wrote:
> >>The tradeoff is a realistic 4.4% power savings vs a 300% increase in
> >>the minimum sleep period. A user will see zero power savings if they
> >>have a USB mouse (probably 99% of desktops). On top of that, we can
> ^^^^^^^^
>
> > Most laptops (including mine, a Thinkpad T40) use a PS/2 mouse. So in
> > the places where power consumption savins matters most, it's usually
> > quite possible to function without needing any USB devices. The 90%
> > figure isn't at all right; in fact, it may be that over 90% of the
> > laptops still use PS/2 mice and keyboards.
>
>Yes, laptops are mostly PS/2, which is why I only claimed a statistic
>for desktops. Desktops pretty much all use USB mice now. If 250Hz were
>only being sold as an option for laptops, we could leave it at that, yet
>its being pushed as a default that's "good for everyone". For desktops
>this is not currently true at all. By the time USB is fixed to do power
>saving, we'll probably have a working tick-skipping patch which makes
>the whole HZ argument moot.
>
> - Jim Bruce
>
>
>
Maybe new desktop systems - but what about the tens of millions of old
systems that don't.

Steve