From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [RFC] sleepy linux Date: Wed, 26 Dec 2007 12:54:30 -0800 Message-ID: <4772BF86.4010906@zytor.com> References: <20071225230731.GA29030@elf.ucw.cz> <4772A3FB.8080108@zytor.com> <200712262108.35643.oliver@neukum.org> <4772BD0C.3040609@zytor.com> <20071226205103.GG8094@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20071226205103.GG8094@elf.ucw.cz> Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: Oliver Neukum , kernel list , Linux-pm mailing list , "Rafael J. Wysocki" List-Id: linux-pm@vger.kernel.org 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