From owner-freebsd-hackers Wed Nov 11 10:10:40 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA14928 for freebsd-hackers-outgoing; Wed, 11 Nov 1998 10:10:40 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from dingo.cdrom.com (castles229.castles.com [208.214.165.229]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id KAA14898 for ; Wed, 11 Nov 1998 10:10:31 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost [127.0.0.1]) by dingo.cdrom.com (8.9.1/8.8.8) with ESMTP id KAA04141; Wed, 11 Nov 1998 10:08:09 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Message-Id: <199811111808.KAA04141@dingo.cdrom.com> X-Mailer: exmh version 2.0.2 2/24/98 To: "Justin T. Gibbs" cc: Greg Lehey , hackers@FreeBSD.ORG Subject: Re: SCSI vs. DMA33.. In-reply-to: Your message of "Wed, 11 Nov 1998 08:38:43 MST." <199811111538.IAA00103@narnia.plutotech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 11 Nov 1998 10:08:08 -0800 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > runs. I think that the testaments on this list and others about > the dramatic improvement CAM has made to the performance of high > load, random seek, workloads also shows the effectiveness of > overlapped I/O. The main reason CAM performs so well is the order > of magnitude increase in the number of concurrent, per-device, transactions > the system supports. Unfortunately, Simon's numbers tend to indicate that CAM doesn't provide the same order of magnitude improvement that the old SCSI subsystem did. At least it's a little more robust. 8) -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message