From owner-freebsd-hardware Wed Dec 18 09:35:05 1996 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id JAA17278 for hardware-outgoing; Wed, 18 Dec 1996 09:35:05 -0800 (PST) Received: from GndRsh.aac.dev.com (GndRsh.aac.dev.com [198.145.92.241]) by freefall.freebsd.org (8.8.4/8.8.4) with ESMTP id JAA17262 for ; Wed, 18 Dec 1996 09:35:01 -0800 (PST) Received: (from rgrimes@localhost) by GndRsh.aac.dev.com (8.7.5/8.7.3) id JAA17658; Wed, 18 Dec 1996 09:34:39 -0800 (PST) From: "Rodney W. Grimes" Message-Id: <199612181734.JAA17658@GndRsh.aac.dev.com> Subject: Re: EDO parit RAM (Was Re: Tyan ...) In-Reply-To: <199612180808.WAA21096@pegasus.com> from Richard Foulk at "Dec 17, 96 10:08:35 pm" To: richard@pegasus.com (Richard Foulk) Date: Wed, 18 Dec 1996 09:34:38 -0800 (PST) Cc: freebsd-hardware@freebsd.org X-Mailer: ELM [version 2.4ME+ PL25 (25)] 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 > } > What's wrong with ECC mode only memory? Where can you find parity > } > } 15% loss of performance if I remember well. See the archives of the list. > } > > That seems doubtful. How about 15% on main memory accesses -- most > accesses are from cache. >From my testing on ASUS PCI/I-P55T2P4 Intel 430HX based boards it was infact a 12% degrade in -MEMORY- intensive benchmarks, infact the same benchmarks I used to find the 1% EDO speed up showed the 12% ECC slow down. This would tend to indicate that the slow down in the main memory system is significant when running in ECC mode, far more than one would expect. > > This sounds like the EDO gain that turned out to be 1%. Except that both where measured using the same set of tests, and thus the 15% (12% was my result) is real system performance loss. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation, Inc. Reliable computers for FreeBSD