From owner-freebsd-hardware Mon Apr 1 17:24:05 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id RAA20426 for hardware-outgoing; Mon, 1 Apr 1996 17:24:05 -0800 (PST) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id RAA20300 for ; Mon, 1 Apr 1996 17:23:22 -0800 (PST) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id LAA08833; Tue, 2 Apr 1996 11:15:30 +0930 From: Michael Smith Message-Id: <199604020145.LAA08833@genesis.atrad.adelaide.edu.au> Subject: Re: Parity Errors To: cschuber@orca.gov.bc.ca Date: Tue, 2 Apr 1996 11:15:29 +0930 (CST) Cc: freebsd-hardware@FreeBSD.org In-Reply-To: <199604011754.JAA21922@passer.osg.gov.bc.ca> from "Cy Schubert - ITSD Open Systems Group" at Apr 1, 96 09:54:47 am MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hardware@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk Cy Schubert - ITSD Open Systems Group stands accused of saying: > 4.x, and Linux (1.1, 1.2, and 1.3) without any parity errors. The > QA Plus diagnostic package, which I've used to find many parity > errors before, e.g. when purchasing memory upgrades, did not > complain about any problems. Diagnotics like QAPlus aren't worth spit. They don't exercise memory in any of the dozens of interesting ways that 'real' operating systems do. > Is it possible that FreeBSD is exercising the hardware in a manner > it has never been used before or is this a known FreeBSD problem? FreeBSD can't generate NMI signals; it's your motherboard hardware that's doing that. It wouldn't surprise me if Linux just ignored them 8) > I can configure the machine for memory and/or cache read or write > wait states independently. Should I add a wait state and where, > memory or cache, read or write? If you can disable parity checking with your BIOS, do that. Failing that, wind your main memory read and write waitstates out as slow as they'll go, and if you can add DMA waitstates then do that too. It's possible that it's not a speed thing though - it may just be that you have a dodgy memory part and there's nothing you can do about it. > Cy Schubert OV/VM: BCSC02(CSCHUBER) -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[