Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758629AbXEKTVd (ORCPT ); Fri, 11 May 2007 15:21:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763699AbXEKTTC (ORCPT ); Fri, 11 May 2007 15:19:02 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:1224 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1763517AbXEKTTA (ORCPT ); Fri, 11 May 2007 15:19:00 -0400 Date: Fri, 11 May 2007 19:18:25 +0000 From: Pavel Machek To: Linus Torvalds Cc: Peter Williams , Esben Nielsen , Ingo Molnar , Balbir Singh , linux-kernel@vger.kernel.org, Andrew Morton , Con Kolivas , Nick Piggin , Mike Galbraith , Arjan van de Ven , Thomas Gleixner , caglar@pardus.org.tr, Willy Tarreau , Gene Heskett , Mark Lord , Zach Carter , buddabrod Subject: Re: [patch] CFS scheduler, -v8 Message-ID: <20070511191824.GA7135@ucw.cz> References: <46386F2B.9050307@linux.vnet.ibm.com> <20070502111742.GA18132@elte.hu> <20070506082911.GA32644@elte.hu> <463FC5D8.2090502@bigpond.net.au> <20070510130954.GC4052@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2057 Lines: 45 Hi! > > Also notice that current cpus were not designed to work 300 years. > > When we have hw designed for 50 years+, we can start to worry. > > Indeed. CPU manufacturers don't seem to talk about it very much, and > searching for it with google on intel.com comes up with > > The failure rate and Mean Time Between Failure (MTBF) data is not > currently available on our website. You may contact Intel? > Customer Support for this information. > > which seems to be just a fancy way of saying "we don't actually want to > talk about it". Probably not because it's actually all that bad, but > simply because people don't think about it, and there's no reason a CPU > manufacturer would *want* people to think about it. > > But if you wondered why server CPU's usually run at a lower frequency, > it's because of MTBF issues. I think a desktop CPU is usually specced to > run for 5 years (and that's expecting that it's turned off or at least > idle much of the time), while a server CPU is expected to last longer and > be active a much bigger percentage of time. > > ("Active" == "heat" == "more damage due to atom migration etc". Which is > part of why you're not supposed to overclock stuff: it may well work well > for you, but for all you know it will cut your expected CPU life by 90%). Actually, when I talked with AMD, they told me that cpus should last 10 years *at their max specced temperature*... which is 95Celsius. So overclocking is not that evil, according to my info. (That would mean way more than 10 years if you use your cpu 'normally'.) But I guess capacitors from cpu power supply will hate you running cpu at 95C... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/