From owner-freebsd-hackers Wed Aug 30 14:17:32 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id OAA01841 for hackers-outgoing; Wed, 30 Aug 1995 14:17:32 -0700 Received: from argus.iadfw.net (argus.iadfw.net [204.178.72.68]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id OAA01823 for ; Wed, 30 Aug 1995 14:17:24 -0700 Received: (from jbryant@localhost) by argus.iadfw.net (8.6.11/8.6.9) id QAA04049; Wed, 30 Aug 1995 16:17:11 -0500 From: Jim Bryant Message-Id: <199508302117.QAA04049@argus.iadfw.net> Subject: Re: S.O.S -2.1Stable and ASUSP54TP4 To: rgrimes@gndrsh.aac.dev.com (Rodney W. Grimes) Date: Wed, 30 Aug 1995 16:17:10 -0500 (CDT) Cc: freebsd-hackers@freebsd.org In-Reply-To: <199508300302.UAA05696@gndrsh.aac.dev.com> from "Rodney W. Grimes" at Aug 29, 95 08:02:01 pm X-Mailer: ELM [version 2.4 PL24] Content-Type: text Content-Length: 1793 Sender: hackers-owner@freebsd.org Precedence: bulk In reply: > > Static memories are suspetable to alpha particule disturbance, it just > takes a heck of a lot more to do it, and given ceramic is out of the > picture it won't occur anyway. In a cmos static memory you have to have > enough disturbance to perturb the gate voltage of one side of the latch > to cause a bit flip, about 10 micro rinkens will do it, but it usually > sends the device into latchup at the same time :-). Also why static [Sandia process] memories are used in space and defense apps, Gawd knows they have enough Alpha sources at Sandia to do it right... > Current FIT per bit are in the 0.0002 to 0.0004 range, that is measure in > billions of power on hours. Today MTBF in a 2MB x 16 bit DRAM subsystem > is 30 to 35 years... I'd say I can live with that given that my disk > is going to go belly up in 57 years anyway :-) :-) :-) If you believe that, I have some beachfront property just west of Anacapa, about 150 meters down... If that you believe that crap, then the 486-66 I just replaced would be pushing 800 years old... Nobody except NASA, DoD, and a few large companies probably have clean rooms environmentally and power controlled enough to obtain these ridiculous MTBF ratings... Shit, On my personal machine alone, in the last 8 months, I've been through about 200 years worth of hard disks, hmmm, all seagate, I have yet to have a modern hard drive from seagate last as long as 'ol betsy [my old st-4096 cover off, over fireplace]... Jim -- All opinions expressed are mine, if you | "I will not be pushed, stamped, think otherwise, then go jump into turbid | briefed, debriefed, indexed, or radioactive waters and yell WAHOO !!! | numbered!" - #1, "The Prisoner" jbryant@argus.iadfw.net, Sr. System/Network Admin, Internet America