From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266249AbUHNW4k (ORCPT ); Sat, 14 Aug 2004 18:56:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266259AbUHNW4k (ORCPT ); Sat, 14 Aug 2004 18:56:40 -0400 Received: from havoc.gtf.org ([216.162.42.101]:3731 "EHLO havoc.gtf.org") by vger.kernel.org with ESMTP id S266249AbUHNW4i (ORCPT ); Sat, 14 Aug 2004 18:56:38 -0400 Date: Sat, 14 Aug 2004 18:56:34 -0400 From: Jeff Garzik To: Alan Cox Cc: Bernd Eckenfels , Linux Kernel Mailing List Subject: Re: Linux SATA RAID FAQ Message-ID: <20040814225634.GA17171@havoc.gtf.org> References: <1092315392.21994.52.camel@localhost.localdomain> <411BA7A1.403@pobox.com> <411BA940.5000300@pobox.com> <1092520163.27405.11.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1092520163.27405.11.camel@localhost.localdomain> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 14, 2004 at 10:49:24PM +0100, Alan Cox wrote: > On Iau, 2004-08-12 at 18:30, Jeff Garzik wrote: > > > The SX4 has an on-board DIMM (128M - 2G), through which all data _must_ > > > pass. The data transfer between host and on-board DIMM is a separate > > > DMA engine and separate interrupt event from the four ATA DMA engines > > > (one per SATA port). There are several possibilities that are worth > > > exploring on this card: > > > > > > * Caching > > Is it battery backed ? If it is battery backed then its useful, if not > then it becomes less useful although not always. The i2o drivers have > some ioctls so you can turn on writeback caching even without battery > backup. While this is suicidal for filesytems its just great for swap.. Nope not battery backed... Jeff