Re: [RFC] sleepy linux

["H. Peter Anvin" <hpa@zytor.com>]

Pavel Machek wrote:
> On Wed 2007-12-26 12:43:56, H. Peter Anvin wrote:
>> Oliver Neukum wrote:
>>> Am Mittwoch, 26. Dezember 2007 19:56:59 schrieb H. Peter Anvin:
>>>>> 3) Network card that is either down
>>>>>    or can wake up system on any packet (and not loose too many packets)
>>>>>
>>>> This is the big crux I see.  You're going to constantly wake up the 
>>>> machine due to broadcast packets, and spend a lot of power just going in 
>>>> and out of S3.
>>> How many machines care a lot about saving power while they are connected
>>> to an ethernet? Wlan might be more of a problem.
>> A lot of them should.  An inordinate amount of machines sit there burning 
>> power for no reason.  You can argue that S3 isn't needed -- that nohz + 
>> C3/C4 + turning off the screen would be enough, and that might be
>> + legit.  
> 
> NOHZ + C4 + turn off screen + turn off disk + turn off SATA is still
> ~8W on thinkpad x60.
> 
> S3 is ~1W.
> 
> That's quite significant difference.
> 
> (But yes, connected-to-ethernet is not most important use scenario.)
> 								Pavel

Still... if we could get the desktops of the world down anywhere close 
to that range when not used, it would be a huge win.

	-hpa