From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [RFC][PATCH] at91_ide driver Date: Sun, 18 Jan 2009 13:58:43 +0300 Message-ID: <49730B63.4080500@ru.mvista.com> References: <200901141345.42583.stf_xl@wp.pl> <20090114131727.5b0e5193@lxorguk.ukuu.org.uk> <49708C55.1020204@ru.mvista.com> <200901161603.03699.stf_xl@wp.pl> <4970A8FF.4080404@ru.mvista.com> <20090116161342.4229667f@lxorguk.ukuu.org.uk> <49723AB5.7000809@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from h155.mvista.com ([63.81.120.155]:20030 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1761043AbZARK6y (ORCPT ); Sun, 18 Jan 2009 05:58:54 -0500 In-Reply-To: <49723AB5.7000809@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Stanislaw Gruszka , Andrew Victor , Nicolas Ferre , Haavard Skinnemoen , linux-ide@vger.kernel.org, Bartlomiej Zolnierkiewicz , ddaney@caviumnetworks.com Hello, I wrote: >>> the PIO transfer speeds (very significantly) though I'm not sure of >>> the current state of affairs... >>> >> >> 16bit only performance is identical (as you'd expect) > > Well, I don't know what to expect, having seen figures like 0.5 (or > 1.5) MB/s cited on this list... Instead of going to bed, I tried booting FC8 (2.6.23.y) off DVD in rescue mode and suppressing libata's DMA use: hdparm -t topped at around 1 MB/s from both SATA hard drive and PATA DVD drive with sata_sil driven the former and pata_atiixp the latter... I wasn't able to compare results with IDE core of course. >> identical with the 32bit pio patches applied >> > 32bit is now > > Hm, I didn't realize 32-bit I/O really can really boost the IDE > speed. I vaguely remember (or misremember) benchmarking drives under > DOS (many years ago) with and without 32-bit access enabled in the > BIOS Setup and not seeing any significant differences. Perhpas it's > worth to re-benchmark this in Linux if I find the time... With hdparm being able to control that via its -c option when using IDE driver, it shouldn't take much time... MBR, Sergei