From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752169AbXC1Omn (ORCPT ); Wed, 28 Mar 2007 10:42:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752146AbXC1Omn (ORCPT ); Wed, 28 Mar 2007 10:42:43 -0400 Received: from iriserv.iradimed.com ([72.242.190.170]:16025 "EHLO iradimed.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752169AbXC1Omn (ORCPT ); Wed, 28 Mar 2007 10:42:43 -0400 Message-ID: <460A7EE7.5070101@cfl.rr.com> Date: Wed, 28 Mar 2007 10:42:47 -0400 From: Phillip Susi User-Agent: Thunderbird 1.5.0.10 (Windows/20070221) MIME-Version: 1.0 To: Justin Piszcz CC: linux@horizon.com, htejun@gmail.com, jeff@garzik.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Why is NCQ enabled by default by libata? (2.6.20) References: <20070327161616.31448.qmail@science.horizon.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 28 Mar 2007 14:42:51.0061 (UTC) FILETIME=[5C6CF650:01C77147] X-TM-AS-Product-Ver: SMEX-7.2.0.1122-3.6.1039-15082.000 X-TM-AS-Result: No--3.572000-5.000000-4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Justin Piszcz wrote: > I would try with write-caching enabled. > Also, the RAID5/RAID10 you mention seems like each volume is on part of > the platter, a strange setup you got there :) Shouldn't NCQ only help write performance if write caching is _disabled_? Since write cache essentially is just non tagged command queuing?