From owner-cvs-all Tue Jan 14 17:25: 5 2003 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id ED15137B407; Tue, 14 Jan 2003 17:25:03 -0800 (PST) Received: from ebb.errno.com (ebb.errno.com [66.127.85.87]) by mx1.FreeBSD.org (Postfix) with ESMTP id 10C3E43F18; Tue, 14 Jan 2003 17:25:03 -0800 (PST) (envelope-from sam@errno.com) Received: from melange (melange.errno.com [66.127.85.82]) (authenticated bits=0) by ebb.errno.com (8.12.5/8.12.1) with ESMTP id h0F1OrnN033331 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO); Tue, 14 Jan 2003 17:24:54 -0800 (PST)?g (envelope-from sam@errno.com)œ X-Authentication-Warning: ebb.errno.com: Host melange.errno.com [66.127.85.82] claimed to be melange Message-ID: <159a01c2bc34$e8e099b0$5a557f42@errno.com> From: "Sam Leffler" To: "Andrew Gallatin" , "Peter Wemm" Cc: "John Baldwin" , "Wilko Bulte" , , , "Nate Lawson" References: <20030114173224.A74488@grasshopper.cs.duke.edu><20030114230057.81B422A89E@canning.wemm.org> <15908.46788.141735.858350@grasshopper.cs.duke.edu> Subject: Re: cvs commit: src/sys/dev/acpica acpi_cpu.c Date: Tue, 14 Jan 2003 17:24:52 -0800 Organization: Errno Consulting MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > Peter Wemm writes: > > Andrew Gallatin wrote: > > > John Baldwin [jhb@FreeBSD.org] wrote: > > > > aggressive policies in the future. You could change the speed on > > > > your desktop by changing the performance speed to be 6 (75%) using > > > > the sysctl for example: > > > > > > The scary thing is that for my destop setup, I can turn my speed down > > > to 25% on my P4 and not really feel a difference in xterms, editors > > > and soforth. (I CAN see a difference, I just don't mind it much). > > > > > > Any idea about how much power this actually saves on a desktop? > > > > FWIW, we see a (measured) difference of about 50W on 2.2GHz P4's simply by > > turning machdep.cpu_idle_hlt on and off. I expect the clock throttling > > would make similar differences. For 1U rack-mount systems (especially in > > California) this is a Big Deal. > > Yes, it is. 2 years ago, just as I was leaving Duke and the Enrons of > the world were raping California consumers, some people in my research > group were looking at doing energy-aware server load balancing. Eg, > you suspend a server to save power if load is low, and at peak times > you bring additional servers on line. We were using PIIIs and APM, > waking with wake-on-lan. I bet everything we did would translate to > P4's and ACPI... > > See http://www.cs.duke.edu/ari/publications/balance-of-power.ps > (That's more of a pie-in-the-sky thing.. I don't know where the paper > with the hard numbers went). I believe the paper you're thinking of was given at the 2001 SOSP. There were actually several papers at the conference on the topic. Sam To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message