From owner-freebsd-stable@FreeBSD.ORG Mon Jun 27 08:22:47 2005 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 16FC816A41C for ; Mon, 27 Jun 2005 08:22:47 +0000 (GMT) (envelope-from ade@FreeBSD.org) Received: from mail.lovett.com (foo.lovett.com [67.134.38.158]) by mx1.FreeBSD.org (Postfix) with ESMTP id EC0D743D49 for ; Mon, 27 Jun 2005 08:22:46 +0000 (GMT) (envelope-from ade@FreeBSD.org) Received: from hellfire.lovett.com ([67.134.38.149]:56407) by mail.lovett.com with esmtpa (Exim 4.51 (FreeBSD)) id 1DmotB-000Hkq-Hw; Mon, 27 Jun 2005 01:22:45 -0700 Message-ID: <42BFB78E.8000805@FreeBSD.org> Date: Mon, 27 Jun 2005 01:23:42 -0700 From: Ade Lovett User-Agent: Mozilla Thunderbird 1.0.2 (Macintosh/20050317) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Marc G. Fournier" References: <20050626233114.G57847@ganymede.hub.org> In-Reply-To: <20050626233114.G57847@ganymede.hub.org> X-Enigmail-Version: 0.91.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: ade@lovett.com Cc: freebsd-stable@freebsd.org Subject: Re: SATA vs SCSI ... X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Jun 2005 08:22:47 -0000 Marc G. Fournier wrote: > > looking at the specs between two cards, the SATA card(s) seem to rate > ~100-150MB/s on each channel (if I'm reading right), with both the 3Ware > and ICP cards having 4 individual channels ... looking at the SCSI > cards, they are rated at 320MB/s, but that is total for the SCSI bus > itself, right? [snip] As is often the case, these kind of comparisons are only working against one side of the equation: "What happens when the system is operational" Now, for your average desktop system, the converse: "What happens when things break" becomes negligable. Slap in new drive, slap in DVD/CD install media, Do Stuff[tm], make working system. In the Non-Stop (probably a trademark of Tandem) server-class world, things work somewhat differently. This is why we run postgresql instead of mysql. This is also the reason we run U320 SCSI enclosures at twice the cost of equivalent SATA systems. The extra cash is well spent when things go wrong. Absolute performance (assuming it can be measured correctly for the specific environment you're in, as opposed to marketing figures) counts for less than 50% of the whole equation when it comes to the purchase decision. -aDe