From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262094AbTL1V4q (ORCPT ); Sun, 28 Dec 2003 16:56:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262109AbTL1V4q (ORCPT ); Sun, 28 Dec 2003 16:56:46 -0500 Received: from outpost.ds9a.nl ([213.244.168.210]:33412 "EHLO outpost.ds9a.nl") by vger.kernel.org with ESMTP id S262094AbTL1V4p (ORCPT ); Sun, 28 Dec 2003 16:56:45 -0500 Date: Sun, 28 Dec 2003 22:56:44 +0100 From: bert hubert To: Johannes Ruscheinski Cc: Joel Jaeggli , linux-kernel@vger.kernel.org Subject: Re: Best Low-cost IDE RAID Solution For 2.6.x? (OT?) Message-ID: <20031228215644.GA32140@outpost.ds9a.nl> Mail-Followup-To: bert hubert , Johannes Ruscheinski , Joel Jaeggli , linux-kernel@vger.kernel.org References: <20031228180424.GA16622@mail-infomine.ucr.edu> <20031228213535.GA21459@mail-infomine.ucr.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031228213535.GA21459@mail-infomine.ucr.edu> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 28, 2003 at 01:35:35PM -0800, Johannes Ruscheinski wrote: > Fisrt of all: thanks for the advice Joel! Two questions: why not use the > hardware raid capability of the Promise tx4000 and if we'd use software > raid instead, what would be the CPU overhead? For the cost differential between linux native RAID and an external device of similar capabilities, outfit yourself with an additional CPU. I don't use RAID5 a lot but to a modern CPU, checksumming dozens of megabytes/second is child's play: raid5: measuring checksumming speed 8regs : 1479.600 MB/sec 32regs : 744.400 MB/sec pIII_sse : 1649.200 MB/sec pII_mmx : 1806.000 MB/sec p5_mmx : 1915.200 MB/sec raid5: using function: pIII_sse (1649.200 MB/sec) This is on a 800MHz Celeron, so a recent >2Ghz system will do lots better still. -- http://www.PowerDNS.com Open source, database driven DNS Software http://lartc.org Linux Advanced Routing & Traffic Control HOWTO