From owner-freebsd-hackers@FreeBSD.ORG Mon May 9 19:02:52 2005 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 35BA516A4EA; Mon, 9 May 2005 19:02:52 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id C4B7043D98; Mon, 9 May 2005 19:02:51 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.13.1/8.13.3) id j49J2jST056234; Mon, 9 May 2005 14:02:45 -0500 (CDT) (envelope-from dan) Date: Mon, 9 May 2005 14:02:45 -0500 From: Dan Nelson To: Eric Anderson Message-ID: <20050509190245.GF38839@dan.emsphone.com> References: <427FA802.90805@chamkila.org> <427FA8CD.8040405@centtech.com> <427FAB5F.6070508@chamkila.org> <427FAF73.7070702@centtech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <427FAF73.7070702@centtech.com> X-OS: FreeBSD 5.4-STABLE X-message-flag: Outlook Error User-Agent: Mutt/1.5.8i cc: freebsd-hackers@freebsd.org cc: Amandeep cc: freebsd-questions@freebsd.org cc: john@essenz.com Subject: Re: Low HDD tranfer rate with FreeBSD 5.3-Release X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 May 2005 19:02:52 -0000 In the last episode (May 09), Eric Anderson said: > > Eric Anderson wrote: > >> Amandeep wrote: > >>> I am using Tyan S2098 MB with 160GB Maxtor ATA Drive and the > >>> transfer rate is very low. FreeBSD 5.3-Release. > >>> Any ideas what is going on here. > >>> > >>> The transfer rate is about 15MB/s > >>> > >>> when I run > >>> #dd if=/dev/zero of=/usr/junk bs=8192 > > > >Shouldnt it be around 54MB/s for a regular IDE drive. > > What about other block sizes? Also - you should paste your actual dd > output here too. > > What's the model number of that drive? Maxtor claims (on one of > their 160G drives) 17.8MB/s from inner diameter disk and 35.6MB/s for > outer diameter for the 5400rpm drives. Yes, try 64k instead of 8k, and also compare read speeds. If you have the time (could take an hour or so), try "dd if=/dev/ad0 of=/dev/null bs=64k", run an "iostat 60" in another window, let the dd run through the entire disk, and compare the relative speeds from start to finish. For the DiamondMax 160, the sustained throughput should be 26MB -> 50MB as you go from inner to outer tracks. -- Dan Nelson dnelson@allantgroup.com