From owner-freebsd-questions Thu Nov 26 19:20:44 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA05443 for freebsd-questions-outgoing; Thu, 26 Nov 1998 19:20:44 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from shell.futuresouth.com (shell.futuresouth.com [198.78.58.28]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA05434 for ; Thu, 26 Nov 1998 19:20:42 -0800 (PST) (envelope-from stormy@futuresouth.com) Received: (from stormy@localhost) by shell.futuresouth.com (8.8.8/8.8.8) id VAA23941 for questions@freebsd.org; Thu, 26 Nov 1998 21:20:35 -0600 (CST) Date: Thu, 26 Nov 1998 21:20:35 -0600 (CST) From: Stormy Henderson Message-Id: <199811270320.VAA23941@shell.futuresouth.com> To: questions@FreeBSD.ORG Subject: Slow CCD Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I have an Adaptec 2940 with 2 matched 1GB SCSI-2 drives, 5400rpm, 10ms access. Using dd bs=1m count=128 if=/dev/da0s1e of=/dev/null, I get 4MB per second, and about the same with 8k blocks. Using CCD with an interleave of 512, and the same dd, I get 1MB per second. Increasing the interleave to 65535 improves performance to a miserable 1.7MB per second. Forgetting interleave and just concatting them doesn't do any better. I have a p133, by the way. Is the abysmal performance normal on my hardware? I'm using 3.0-19981123-SNAP. -- Stormy Henderson To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message