From owner-freebsd-hackers Wed Nov 11 07:43:53 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA27569 for freebsd-hackers-outgoing; Wed, 11 Nov 1998 07:43:53 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from gilgamesch.bik-gmbh.de (gilgamesch.bik-gmbh.de [194.233.237.91]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA27564 for ; Wed, 11 Nov 1998 07:43:50 -0800 (PST) (envelope-from cracauer@gilgamesch.bik-gmbh.de) Received: (from cracauer@localhost) by gilgamesch.bik-gmbh.de (8.8.8/8.7.3) id QAA29729; Wed, 11 Nov 1998 16:41:37 +0100 (MET) Message-ID: <19981111164136.A29513@cons.org> Date: Wed, 11 Nov 1998 16:41:36 +0100 From: Martin Cracauer To: john cooper , grog@lemis.com, hackers@FreeBSD.ORG, mike@smith.net.au, ticso@cicely.de Subject: Re: SCSI vs. DMA33.. References: <98Nov11.134648jst.21907@ns.isi.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93.1i In-Reply-To: <98Nov11.134648jst.21907@ns.isi.co.jp>; from john cooper on Wed, Nov 11, 1998 at 01:41:00PM +0900 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In <98Nov11.134648jst.21907@ns.isi.co.jp>, john cooper wrote: > Just wondering if anyone has any _objective_ opinion on > the performance of say wide SCSI2 vs. DMA33 IDE drives [running > on contemporary motherboards]. The theoretical throughputs of > 40MBs and 33MBs don't tell me a whole lot. I know SCSI was the > choice for performance in the past, however I'm curious what > others are seeing in actual usage these days. I'm just trying to build a CCD system with two PCI UDMA controllers by Promise and 4 IBM DDTA 8 GB drives. Given that I often stream over very large files and that I paid much less than half the money per Megabyte than for SCSI disks the IDE solution sounds good. Guess what: While I can use the two PCI cards simultaneously, I can't do so for the two channels on each card, although they are even two completely independent chips on each Promize card. Since I don't have enough PCI slots for 4 cards (and these things cost money) and my motherboard doesn't do UDMA, I'm stuck with performance like my SCSI CCD with two Atlas drives. That isn't too bad, but not what I hoped for. Maybe it's a problem with our Promise driver? I already contacted John Dyson, but no response yet. Anyone else can think of a solution? Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer BSD User Group Hamburg, Germany http://www.bsdhh.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message