From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261973AbTJOQEe (ORCPT ); Wed, 15 Oct 2003 12:04:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262009AbTJOQEd (ORCPT ); Wed, 15 Oct 2003 12:04:33 -0400 Received: from users.linvision.com ([62.58.92.114]:26818 "HELO bitwizard.nl") by vger.kernel.org with SMTP id S261973AbTJOQEc (ORCPT ); Wed, 15 Oct 2003 12:04:32 -0400 Date: Wed, 15 Oct 2003 18:04:31 +0200 From: Erik Mouw To: Nikita Danilov Cc: Josh Litherland , linux-kernel@vger.kernel.org Subject: Re: Transparent compression in the FS Message-ID: <20031015160430.GH24799@bitwizard.nl> References: <1066163449.4286.4.camel@Borogove> <20031015133305.GF24799@bitwizard.nl> <16269.20654.201680.390284@laputa.namesys.com> <20031015142738.GG24799@bitwizard.nl> <16269.23199.833564.163986@laputa.namesys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16269.23199.833564.163986@laputa.namesys.com> User-Agent: Mutt/1.3.28i Organization: Harddisk-recovery.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 15, 2003 at 06:33:03PM +0400, Nikita Danilov wrote: > Erik Mouw writes: > > You have a point, but remember that modern IDE drives can do about > > 50MB/s from medium. I don't think you'll find a CPU that is able to > > handle transparent decompression on the fly at 50MB/s, even not with a > > simple compression scheme as used in NTFS (see the NTFS docs on > > SourceForge for details). > > Trend is that CPU is getting faster and faster with respect to the > disk. So, even if it were hard to find such a CPU to-day, it will be > common place to-morrow. I'm not too sure about this. It's my feeling that CPU speed and disk throughput grow about as fast. I don't have hard figures, so I can be proven wrong on this. FYI: you hardly see compressed files on NTFS. If you do, it's either because the user thought it was a fun feature (in which case only a small amount of files are compressed), or because it's an old (small) disk filled to the brim with data (in which case most of the volume is compressed). In the latter case compression indeed makes things faster, but only when using the disk with a modern CPU, not when using it in the original machine. Erik -- +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 -- | Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands | Data lost? Stay calm and contact Harddisk-recovery.com