From owner-freebsd-alpha Mon Apr 1 22: 6:15 2002 Delivered-To: freebsd-alpha@freebsd.org Received: from freebie.xs4all.nl (freebie.xs4all.nl [213.84.32.253]) by hub.freebsd.org (Postfix) with ESMTP id 467D237B416 for ; Mon, 1 Apr 2002 22:06:08 -0800 (PST) Received: (from wkb@localhost) by freebie.xs4all.nl (8.11.6/8.11.6) id g32663h41675; Tue, 2 Apr 2002 08:06:03 +0200 (CEST) (envelope-from wkb) Date: Tue, 2 Apr 2002 08:06:03 +0200 From: Wilko Bulte To: Terry Lambert Cc: Christian Weisgerber , freebsd-alpha@FreeBSD.ORG Subject: Re: Source of "processor correctable error"? Message-ID: <20020402080603.D41537@freebie.xs4all.nl> References: <3CA8EADE.C11C8DF7@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3CA8EADE.C11C8DF7@mindspring.com>; from tlambert2@mindspring.com on Mon, Apr 01, 2002 at 03:18:54PM -0800 X-OS: FreeBSD 4.5-STABLE X-PGP: finger wilko@freebsd.org Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Mon, Apr 01, 2002 at 03:18:54PM -0800, Terry Lambert wrote: > Christian Weisgerber wrote: > > Since the weekend my PC164 has taken to almost continuously spewing > > gobs of > > > > Warning: received processor correctable error. > > > > In fact I first noticed this because writing the error messages to > > the serial console took so much time the machine became sluggish. > > I've switched to a graphics console now. > > > > Anyway, is there a way to narrow down the source of the underlying > > hardware problem? What are the candidates anyway? On-chip cache, > > off-chip cache, main memory? > > FWIW, if they are correctable, it's complaining about memory > errors which are correctable using the ECC bits, in the use of > ECC memory. The PC164 has ECC throughout, also on the caches etc. > There are generally three causes of this problem which I have > seen in natures: > > 1) Thermal cooling of the system is insufficient, which > introduces thermal related errors (fix: better cooling). Possible. I've seen a overheating Alpha CPU do warped things. > 3) The "ECC" memory was face ECC instead of real ECC, so > the correction codes were incorrect, either as a result > of a cheap vendor ripping a buyer off, or a cheap buyer > not jumpering the system to not use ECC... or the system > not having the option to be jumpered that way (fix: use > real ECC memory, and not forgeries). Fake parity won't even allow you to get a SRM console prompt on Alphas who need ECC. They want the real stuff. > It's always possible that you have bad RAM, or that the PCI > bus-on time is set to high in the PCI chipset for the amount > of rAM in the system, such that the DRAM referesh is delayed > enough under load that your memory starts losing bits, Etc.. Alphas don't allow you to figgle with this in the BIOS as they don't have a BIOS setup like that :) -- | / o / /_ _ wilko@FreeBSD.org |/|/ / / /( (_) Bulte Arnhem, the Netherlands We are FreeBSD. Resistance is futile. Prepare to be committed. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message