From mboxrd@z Thu Jan 1 00:00:00 1970 From: kenneth johansson Subject: Re: ahci problems with sata disk. Date: Tue, 16 Jan 2007 02:43:47 +0100 Message-ID: <1168911827.7718.4.camel@duo> References: <1168785128.7865.13.camel@duo> <45AB45B2.2080602@gmail.com> <1168859112.6980.8.camel@duo> <45AB86C0.2020507@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from 1-1-4-20a.ras.sth.bostream.se ([82.182.72.90]:2811 "EHLO garbo.kenjo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932179AbXAPBnx (ORCPT ); Mon, 15 Jan 2007 20:43:53 -0500 In-Reply-To: <45AB86C0.2020507@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org On Mon, 2007-01-15 at 22:50 +0900, Tejun Heo wrote: > kenneth johansson wrote: > > On Mon, 2007-01-15 at 18:13 +0900, Tejun Heo wrote: > >> kenneth johansson wrote: > >>> I changed my bios setting for SATA from IDE to AHCI. > >>> > >>> This resulted in some "interesting" read throughput. > >>> > >>> plots can be found at http://kenjo.org/~ken/sata/ > >>> The plots was done on a live disk so some noise is expected but in the > >>> ahci mode the throughput get stuck at 17 MB way to much. > >> It's probably not an ahci problem but more of NCQ implementation problem > >> in the drive firmware. Please report the result of 'hdparm -I /dev/sdX' > >> and try adjust queue depth and see what happens. > >> > >> http://linux-ata.org/faq.html > >> > > > > It was, when I turn of NCQ with "echo 1 > >> /sys/block/sda/device/queue_depth" I get the same performance as when > > the BIOS is set to IDE. > > Can you play with queue depth a bit? e.g. Benchmark queue depth of 4, 8 > and 16. I did some more test "http://kenjo.org/~ken/sata/" and queue 1 and maybe 2 works but everything larger than that has problems.