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

[ambx1@neo.rr.com]

----- Original Message -----
From: Theodore Ts'o <tytso@mit.edu>
Date: Monday, August 1, 2005 4:42 pm
Subject: Re: Power consumption HZ100, HZ250, HZ1000: new numbers

> 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 
> throw in 
> > Con's disturbing AV benchmark results (1).  As a result, some of 
> us 
> > don't think 250HZ is a great tradeoff to make 
> _for_the_default_value_.
> 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.
> 
>                                        	- Ted

Also, my understanding was that when we properly support usb suspend,
this won't be an issue anyway for much usb hardware.  I think it's
possible to put some mice to sleep when there isn't any motion and
then wakeup later.

4.4% savings may not be much, but these things do add up.  For a
laptop's workload, I think this is worth it.

Thanks,
Adam