From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753156AbXDEQ1B (ORCPT ); Thu, 5 Apr 2007 12:27:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753164AbXDEQ1B (ORCPT ); Thu, 5 Apr 2007 12:27:01 -0400 Received: from bay0-omc3-s37.bay0.hotmail.com ([65.54.246.237]:52966 "EHLO bay0-omc3-s37.bay0.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753156AbXDEQ1A (ORCPT ); Thu, 5 Apr 2007 12:27:00 -0400 Message-ID: X-Originating-IP: [88.114.147.249] X-Originating-Email: [paapaa125@hotmail.com] From: "Paa Paa" To: linux-kernel@vger.kernel.org Subject: Re: Lower HD transfer rate with NCQ enabled? Date: Thu, 05 Apr 2007 16:26:59 +0000 Mime-Version: 1.0 Content-Type: text/plain; format=flowed X-OriginalArrivalTime: 05 Apr 2007 16:26:59.0813 (UTC) FILETIME=[3C46D950:01C7779F] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mark Lord wrote: >>>This is mostly a problem with the WD Raptor drive, and some other WD >>>drives. >>>I have not yet encountered/noticed the problem with other brands. >> >>Sounds like this is a serious bug in the WD firmware. > >For personal systems, yes. For servers, probably not a bug. In my case the choice of IO scheduler affected the result of "hdparm -t" significantly. With Deadline I got identical result with NCQ and wihout NCQ. It was only with CFQ when I got worse results with NCQ than without it. What might be the reason CFQ+NCQ gived so much worse throughput with "hdparm -t"? _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/