Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id D22349FB5E7 for ; Fri, 25 May 2007 23:15:48 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 65578-01 for ; Fri, 25 May 2007 23:15:35 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from wolff.to (wolff.to [66.93.197.194]) by postgresql.org (Postfix) with SMTP id 6AF789FB5AA for ; Fri, 25 May 2007 23:15:41 -0300 (ADT) Received: (qmail 14373 invoked by uid 500); 26 May 2007 02:15:53 -0000 Date: Fri, 25 May 2007 21:15:53 -0500 From: Bruno Wolff III To: Craig James Cc: pgsql-performance@postgresql.org Subject: Re: ECC RAM really needed? Message-ID: <20070526021553.GA8875@wolff.to> Mail-Followup-To: Bruno Wolff III , Craig James , pgsql-performance@postgresql.org References: <4657912B.3000508@emolecules.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4657912B.3000508@emolecules.com> User-Agent: Mutt/1.4.2.1i X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/550 X-Sequence-Number: 24940 On Fri, May 25, 2007 at 18:45:15 -0700, Craig James wrote: > We're thinking of building some new servers. We bought some a while back > that have ECC (error correcting) RAM, which is absurdly expensive compared > to the same amount of non-ECC RAM. Does anyone have any real-life data > about the error rate of non-ECC RAM, and whether it matters or not? In my > long career, I've never once had a computer that corrupted memory, or at > least I never knew if it did. ECC sound like a good idea, but is it > solving a non-problem? In the past when I purchased ECC ram it wasn't that much more expensive than nonECC ram. Wikipedia suggests a rule of thumb of one error per month per gigabyte, though suggests error rates vary widely. They reference a paper that should provide you with more background.