Re: [RFC] sleepy linux

H. Peter Anvin
2007-12-26T20:54:30Z

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