From owner-freebsd-questions@FreeBSD.ORG Fri Mar 2 11:02:38 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B19D716A403 for ; Fri, 2 Mar 2007 11:02:38 +0000 (UTC) (envelope-from arne_woerner@yahoo.com) Received: from web30315.mail.mud.yahoo.com (web30315.mail.mud.yahoo.com [209.191.69.77]) by mx1.freebsd.org (Postfix) with SMTP id 5D6AB13C4A3 for ; Fri, 2 Mar 2007 11:02:38 +0000 (UTC) (envelope-from arne_woerner@yahoo.com) Received: (qmail 80688 invoked by uid 60001); 2 Mar 2007 10:35:56 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=1IekMctHDEZWnuBPlzhebeUXhKRGZ4SaDqEbuwdu8aYndp2TARzkBWy+UcXE8qa4MYUJkXWQjt7jPT7Tel6Z8GQXIn2nM6ksVdxWiT4lBh4Cnlj3qUNiuxBTzE+/coVvT14YDzIA0t8EhlqVvEL8TslFanIQaFBdgIYtaVxvCSk=; X-YMail-OSG: cxwZgqAVM1mTUs23ECHL8WM9QuV8Y.4_mb6LhJz1.KUreygZWprx8_g2ZQZGcWdegfmZjMAYEvgaS7mQOVyQSSjKKfpCckuOGt2iR9acHQ7wCu8IQg5EJSRxneSUsx7EJNVKvOVziuP4cRo._01ejkBcTw-- Received: from [85.212.11.231] by web30315.mail.mud.yahoo.com via HTTP; Fri, 02 Mar 2007 02:35:56 PST Date: Fri, 2 Mar 2007 02:35:56 -0800 (PST) From: "R. B. Riddick" To: "O. Hartmann" , freebsd-performance@freebsd.org, freebsd-questions@freebsd.org In-Reply-To: <45E7F09B.7070005@zedat.fu-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Message-ID: <455296.79993.qm@web30315.mail.mud.yahoo.com> Cc: Subject: Re: (S)ATA performance in FBSD 6.2/7.0 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: Fri, 02 Mar 2007 11:02:38 -0000 --- "O. Hartmann" wrote: > Before digging into this problem deeper with benchmarks, could anyone > explain why FreeBSD reaches this 33 MB/s limit (sounds like UDMA 33 > defaults, but on both boxes nForce4 and ICH5 controller are recognized > and show up with SATA300 or SATA150 capabilities, respective)? May I > have some knobs I'm not aware of to tune disk performance? > I think, this 33MB/sec limit comes like this: The regular copy process (I think u used "cp") reads with speed S from disk A and writes with speed S to disk B. But: While it reads, it doesnt write AND while it writes, it doesnt read. So you might want to try this: dd if=/diskA/fileA bs=128k | dd of=/diskB/fileB bs=128k You could also try just to read or to write. Or to read&write with _independent_ processes. -Arne ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php