From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263505AbTJQTS1 (ORCPT ); Fri, 17 Oct 2003 15:18:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263506AbTJQTS1 (ORCPT ); Fri, 17 Oct 2003 15:18:27 -0400 Received: from main.gmane.org ([80.91.224.249]:46493 "EHLO main.gmane.org") by vger.kernel.org with ESMTP id S263505AbTJQTS0 (ORCPT ); Fri, 17 Oct 2003 15:18:26 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: mru@users.sourceforge.net (=?iso-8859-1?q?M=E5ns_Rullg=E5rd?=) Subject: Re: Software RAID5 with 2.6.0-test Date: Fri, 17 Oct 2003 21:18:24 +0200 Message-ID: References: <1065690658.10389.19.camel@slurv> <3F903768.7060803@rackable.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@sea.gmane.org User-Agent: Gnus/5.1002 (Gnus v5.10.2) XEmacs/21.4 (Rational FORTRAN, linux) Cancel-Lock: sha1:emZKyOzpacSRRFnfh1npf/a/6TE= Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Samuel Flory writes: >> What about the RAID controllers in the $400 category? Surely, they >> must be doing something better than the $50 fakeraid controllers. >> > > Yes, but follow this logic. > > 1)You are willing to devote 10% of 2Ghz xeon to software raid. > 2)A $500+ controller has a 100Mhz proccessor. > > Thus just from this you could guess that software raid has x2 as > many clock cycles availble to it. It's even worse when you realize > the 2Ghz xeon is a better proccessor in many more ways than just > clock cycles. How about this logic: 1) If the processor on the RAID controller can handle the full bandwidth of the disks, it's fast enough. 2) If someone else does the 10% work, the CPU can do 10% more work. -- Måns Rullgård mru@users.sf.net