From owner-freebsd-stable Tue Apr 2 22:25:43 1996 Return-Path: owner-stable Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id WAA22398 for stable-outgoing; Tue, 2 Apr 1996 22:25:43 -0800 (PST) Received: from GndRsh.aac.dev.com (GndRsh.aac.dev.com [198.145.92.241]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id WAA22360 for ; Tue, 2 Apr 1996 22:25:38 -0800 (PST) Received: (from rgrimes@localhost) by GndRsh.aac.dev.com (8.6.12/8.6.12) id NAA04334; Tue, 2 Apr 1996 13:45:43 -0800 From: "Rodney W. Grimes" Message-Id: <199604022145.NAA04334@GndRsh.aac.dev.com> Subject: Re: SCSI Performance under -stable/-current To: steve@edmweb.com (Steve Reid) Date: Tue, 2 Apr 1996 13:45:43 -0800 (PST) Cc: msmith@atrad.adelaide.edu.au, Zeki@Dilbert.Oasysinc.com, stable@FreeBSD.org In-Reply-To: from Steve Reid at "Apr 2, 96 12:31:52 pm" X-Mailer: ELM [version 2.4ME+ PL11 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-stable@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > > > One should always temper theory with reality. You can go a lot faster by > > > striping your sectors across several surfaces, for example. > > > Very very very rare. > > I thought having more that one platter would do this?? It doesn't > actually split one sector over multiple surfaces, but adjacent sectors > could be (and are?). Can grab several sectors in parallel that way. Though the theory of all this sounds great, I do not know of a disk manufacturer doing this in thier standard drive line. (Yes, there are very special and very expensive drives that have this feature, but again, very very very rare.) The cost of doing this is non-trivial, and I don't care to get into the gory details of it all, just take it at my word, this is something that is not very common. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Reliable computers for FreeBSD