From owner-cvs-all Fri Oct 26 19:49:31 2001 Delivered-To: cvs-all@freebsd.org Received: from beppo.feral.com (beppo.feral.com [192.67.166.79]) by hub.freebsd.org (Postfix) with ESMTP id 571BF37B403; Fri, 26 Oct 2001 19:49:27 -0700 (PDT) Received: from mailhost.feral.com (mjacob@mailhost.feral.com [192.67.166.1]) by beppo.feral.com (8.11.3/8.11.3) with ESMTP id f9R2nQH13741; Fri, 26 Oct 2001 19:49:26 -0700 (PDT) (envelope-from mjacob@feral.com) Date: Fri, 26 Oct 2001 19:49:26 -0700 (PDT) From: Matthew Jacob X-Sender: mjacob@beppo Reply-To: mjacob@feral.com To: Greg Lehey Cc: Doug Rabson , Luigi Rizzo , John Baldwin , Jonathan Lemon , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: RAID-5 parity calculations (was: cvs commit: src/sys/dev/fxp if_fx) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=X-UNKNOWN Content-Transfer-Encoding: 8BIT Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > Instantaneously? Well, how long does it take to checksum 6 kB (the > > average request size)? That's 1500 words, say 10000 instructions. At > > 1 GHz, that's 10 µs, which is completely negligible compared to the > > minimum four I/O transactions needed, which add up to about 25 ms. > > BTW- for the Convex in question, the average request size was 64K. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message