From owner-freebsd-stable Sat Jul 22 17:32:45 2000 Delivered-To: freebsd-stable@freebsd.org Received: from gndrsh.dnsmgr.net (GndRsh.dnsmgr.net [198.145.92.4]) by hub.freebsd.org (Postfix) with ESMTP id B64CB37B5BD for ; Sat, 22 Jul 2000 17:32:42 -0700 (PDT) (envelope-from freebsd@gndrsh.dnsmgr.net) Received: (from freebsd@localhost) by gndrsh.dnsmgr.net (8.9.3/8.9.3) id RAA44244; Sat, 22 Jul 2000 17:32:27 -0700 (PDT) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <200007230032.RAA44244@gndrsh.dnsmgr.net> Subject: Re: Signal 11 on 4-Stable buildworld; bad memory or what? In-Reply-To: <4.3.2.20000722162331.00d5ec70@207.227.119.2> from "Jeffrey J. Mountin" at "Jul 22, 2000 05:18:03 pm" To: jeff-ml@mountin.net (Jeffrey J. Mountin) Date: Sat, 22 Jul 2000 17:32:27 -0700 (PDT) Cc: lioux@uol.com.br (Mario Sergio Fujikawa Ferreira), freebsd-stable@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL54 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > At 12:53 PM 7/21/00 -0700, Rodney W. Grimes wrote: > >Note also that OC'ing can cause _permanent_ damage to semiconductors, > >and that clocking down to spec may still leave you with hardware that > >does not function correctly. The predominant failure mode is caused > >by something called electromigration that has to do with metal migrating > >into the semiconductor due to operating at excessive temperature. > > Certainly, but excellent cooling is a must when OC'ing, even if one is just > doing a quick test to see if the CPU can be OC'ed. Electromigration can > happen when running a CPU within specs, except for sufficient cooling. My point was the if you have OC'ed your CPU, I don't care if you reset to defaults, I don't want to here about your problems until you have replaced all the OC'ed hardware with known good hardware that has not been OC'ed _EVER_. Another point I totally left asside was the effects of Impact Ionization, another non reversing process that happens when you OC chips. Once we pushed past 0.25uM it became necessary to start simulating chip life times due to impact ionization deteriorating the channel. Chips are now being designed with life times of 10 years, and if you OC them they are going to die in months, not years. I have seen some simulation studies that say raising the supply voltage even 0.02 V will lead to device failure 150 times faster. -- Rod Grimes - KD7CAX @ CN85sl - (RWG25) rgrimes@gndrsh.dnsmgr.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message