From owner-freebsd-questions Fri Jan 14 14:24:40 2000 Delivered-To: freebsd-questions@freebsd.org Received: from mail2.aracnet.com (mail2.aracnet.com [216.99.193.35]) by hub.freebsd.org (Postfix) with ESMTP id 9E9E6151D6 for ; Fri, 14 Jan 2000 14:24:24 -0800 (PST) (envelope-from hamellr@aracnet.com) Received: from shell1.aracnet.com (IDENT:root@shell1.aracnet.com [216.99.193.21]) by mail2.aracnet.com (8.9.3/8.9.3) with ESMTP id OAA10977; Fri, 14 Jan 2000 14:24:01 -0800 Received: from localhost by shell1.aracnet.com (8.9.3) id OAA11775; Fri, 14 Jan 2000 14:25:17 -0800 X-Authentication-Warning: shell1.aracnet.com: hamellr owned process doing -bs Date: Fri, 14 Jan 2000 14:25:17 -0800 (PST) From: Rick Hamell To: Micke Josefsson Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Expected SCSI speed question In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I have a 200 MHz K6 system (FBSD 3.2), Adaptec 2940UW SCSI-adaptor and Seagate > ST19171W Hard disk. The Seagate (Barracuda 9) disk is specced to up to 40 > Mbytes/sec Max sync. SCSI transfer rate. But whatever tests I run (copying > large files to and fro, dd from disk to /dev/null for example) the actual speed > is never more than around 0.5 MB/s according to 'systat -io 1' or 'systat -vm > 1'. > > Is there a knob to turn to speed it up or is this a bottleneck due to the > processor? I've noticed that the Adaptec 2940UW seems to be a fairly slow card, at this point I'm pulling every single one I come across and replacing with Tekram cards. The biggest differance I saw was doing a drive mirror under Novell 3.12 a couple of weeks ago. Dual 2940s with their own seperate drives took 3 hours. Using the exact same model drive and two of the Tekram cards took under 20 minutes. Under FreeBSD I've seen similar performance. :( Rick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message