From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [RFC] sleepy linux Date: Wed, 26 Dec 2007 21:51:03 +0100 Message-ID: <20071226205103.GG8094@elf.ucw.cz> References: <20071225230731.GA29030@elf.ucw.cz> <4772A3FB.8080108@zytor.com> <200712262108.35643.oliver@neukum.org> <4772BD0C.3040609@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4772BD0C.3040609@zytor.com> Sender: linux-kernel-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Oliver Neukum , kernel list , Linux-pm mailing list , "Rafael J. Wysocki" List-Id: linux-pm@vger.kernel.org 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 -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html