Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753247Ab0L0Ae7 (ORCPT ); Sun, 26 Dec 2010 19:34:59 -0500 Received: from dtp.xs4all.nl ([80.101.171.8]:25783 "HELO abra2.bitwizard.nl" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S1752634Ab0L0Ae5 (ORCPT ); Sun, 26 Dec 2010 19:34:57 -0500 Date: Mon, 27 Dec 2010 01:34:56 +0100 From: Rogier Wolff To: Mark Knecht Cc: Jeff Moyer , Rogier Wolff , Greg Freemyer , Bruno =?iso-8859-1?Q?Pr=E9mont?= , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: Slow disks. Message-ID: <20101227003456.GG18227@bitwizard.nl> References: <20101220141553.GA6088@bitwizard.nl> <20101220190630.66084e1d@neptune.home> <20101222104306.GB30941@bitwizard.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: BitWizard.nl User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1821 Lines: 37 On Sun, Dec 26, 2010 at 03:38:51PM -0800, Mark Knecht wrote: > First, the drives are 4K sector so it's really important to get them > on the right partition boundary. Installing Gentoo requires that we > un-tar some large-ish files. IIRC on a 512 byte boundary these drives > took 20-30 minutes to do this. On a 4K boundary they took about 1 > minute. I know that doesn't make sense but those were my numbers, and > it's a very high end Intel i7-980x MB so there wasn't any other > problem I could find. Mark, Thanks for your contribution. You're seeing a 20-30 fold performance issue, where only about 2x would be expected. So to test this theory I'll see if we can evacuate a partition, untar a large-ish file as a benchmark, and then see if we can improve that by changing the alignment of the partition. (hmm. Maybe we should do things the other way around. First find a tar-workload that takes about 1 minute on a properly working drive, and then we can wait up to 30 minutes for it to finish on the improper setup.). Being able to reproduce a problem at will is a great progress to being able to solve it! Roger. -- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 ** ** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 ** *-- BitWizard writes Linux device drivers for any device you may have! --* Q: It doesn't work. A: Look buddy, doesn't work is an ambiguous statement. Does it sit on the couch all day? Is it unemployed? Please be specific! Define 'it' and what it isn't doing. --------- Adapted from lxrbot FAQ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/