From owner-freebsd-questions@FreeBSD.ORG Thu Mar 16 19:08:18 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A461616A422 for ; Thu, 16 Mar 2006 19:08:18 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id C161443D46 for ; Thu, 16 Mar 2006 19:08:15 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 26B665F56; Thu, 16 Mar 2006 14:08:15 -0500 (EST) Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 72681-09; Thu, 16 Mar 2006 14:08:14 -0500 (EST) Received: from [192.168.1.3] (pool-68-160-194-11.ny325.east.verizon.net [68.160.194.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 3308F5F4F; Thu, 16 Mar 2006 14:08:14 -0500 (EST) Message-ID: <4419B7A4.8050002@mac.com> Date: Thu, 16 Mar 2006 14:08:20 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: Don O'Neil References: <040601c64928$c3a4e140$0300020a@mickey> In-Reply-To: <040601c64928$c3a4e140$0300020a@mickey> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at codefab.com Cc: freebsd-questions@freebsd.org Subject: Re: Raidtest/3Ware 6000 Throughput X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Mar 2006 19:08:18 -0000 Don O'Neil wrote: > I would have thought I would at least see the raw single drive throughput, > plus maybe a bit more. When choosing RAID levels, you are making a tradeoff between performance, reliability, and cost. Choosing RAID-5 means you value performance the least of the three: If you prefer... ...consider using: ----------------------------------------------- performance, reliability: RAID-1 mirroring performance, cost: RAID-0 striping reliability, performance: RAID-1 mirroring (+ hot spare, if possible) reliability, cost: RAID-5 (+ hot spare) cost, reliability: RAID-5 cost, performance: RAID-0 striping If you've got enough drives, using RAID-10 or RAID-50 will also improve performance compared to stock RAID-1 or RAID-5 modes. > I've benched these drives independantly at 20+ > MB/second... Is the 3ware card really slowing things down that much with the > RAID-5 overhead? Yes. It will be less noticeable with big transactions, and more noticeable with lots of tiny ones. > What "real HW RAID-5" controller would you suggest? I'd like to stick with > IDE/ATA since I have a bunch of drives already. Maybe the 3ware 9500S -4 or -8...? > Am I maybe CPU bound, or have another issue? You're probably I/O bound, not CPU bound. -- -Chuck