From owner-freebsd-hardware Sat Aug 12 02:59:43 1995 Return-Path: hardware-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id CAA19666 for hardware-outgoing; Sat, 12 Aug 1995 02:59:43 -0700 Received: from gndrsh.aac.dev.com (gndrsh.aac.dev.com [198.145.92.241]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id CAA19658 for ; Sat, 12 Aug 1995 02:59:41 -0700 Received: (from rgrimes@localhost) by gndrsh.aac.dev.com (8.6.11/8.6.9) id CAA05630; Sat, 12 Aug 1995 02:58:54 -0700 From: "Rodney W. Grimes" Message-Id: <199508120958.CAA05630@gndrsh.aac.dev.com> Subject: Re: Upgrade to my machine To: jayk@rahul.net (Jay Kirchhoff) Date: Sat, 12 Aug 1995 02:58:54 -0700 (PDT) Cc: smp@teal.csn.org, jmb@kryten.atinc.com, hardware@freebsd.org In-Reply-To: from "Jay Kirchhoff" at Aug 11, 95 01:50:17 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1533 Sender: hardware-owner@freebsd.org Precedence: bulk > > > I thing IBM has a drive like that. It had two 2 gig 3.5 drives mounted > in a full height frame. The ad said the two drive were addressed as one > and the data was stripped across them. IBM does make a drive like that, but the transfer rate is not what you would get on a 4 platter drive using head striping, as with the dual 2 gig drives you simple get 2 heads of stripe width, with the 4 platter drive you put 1 bit on each surface and use 8 heads at a time. This would put a 5400 RPM drive into the 32MB/sec head to drive electronics transfer rate, something that could finally swamp a fast wide scsi-ii bus :-). As it stands today it is very hard to find any drive capable of >6MB/s of head to electronics transfer rate. If I recall the dual IBM 5.25 inch drive setup it has a transfer rate just under 6MB/s :-(. > On Fri, 11 Aug 1995, Steve Passe wrote: > > > > > my "dream" system would use a 3940W to stripe pairs of spindle-synced > > drives, am also interested if anything exists along these lines. > > > > also, I seem to remember seeing an ad recently for a WIDE SCSI drive > > that claimed to do internal head stripping allowing it to approach > > a sustained 20 MB transfer rate on the SCSI bus. anyone know what > > drive this was, I can't recall... (old age is a terrible thing!) > > > > Steve Passe > > smp@teal.csn.org > > > -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Reliable computers for FreeBSD