From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751147AbYE1NnL (ORCPT ); Wed, 28 May 2008 09:43:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751074AbYE1Nm7 (ORCPT ); Wed, 28 May 2008 09:42:59 -0400 Received: from caffeine.csclub.uwaterloo.ca ([129.97.134.17]:33128 "EHLO caffeine.csclub.uwaterloo.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035AbYE1Nm6 (ORCPT ); Wed, 28 May 2008 09:42:58 -0400 Date: Wed, 28 May 2008 09:42:57 -0400 To: Phillip Susi Cc: Gene Heskett , Stefan Richter , linux-kernel@vger.kernel.org, Jens Axboe Subject: Re: floppy question of the hour Message-ID: <20080528134257.GA16164@csclub.uwaterloo.ca> References: <200805232114.20937.gene.heskett@gmail.com> <4837DFC6.9010202@s5r6.in-berlin.de> <200805240852.58268.gene.heskett@gmail.com> <483C81DE.8060002@cfl.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <483C81DE.8060002@cfl.rr.com> User-Agent: Mutt/1.5.13 (2006-08-11) From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 27, 2008 at 05:49:18PM -0400, Phillip Susi wrote: > Yes, the interleave slows you down, since after accessing sector 1, the > head must wait to pass over 3 other sectors before finally reaching > sector 2, therefore, you can only read 1/4 of the sectors on the track > each revolution of the disk. That leaves 4 revolutions at 300 rpm > giving 0.8s to read a track, or 64 seconds to read all 80 tracks, plus > seek time. That still does not explain 3 minutes though... not sure > what else could be slowing you down. Just do what the Amiga did: Read the entire track into a buffer in memory, then deal with the sectors, and write the entire track back. :) -- Len Sorensen