From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Warner Subject: Re: libata problems with 66Mhz Promise SATA150 TX4 Date: Tue, 14 Sep 2004 19:18:51 -0500 Sender: linux-ide-owner@vger.kernel.org Message-ID: <20040914191851.A7263@florence.linkmargin.com> References: <41473287.7050101@epita.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from ms-smtp-02.rdc-kc.rr.com ([24.94.166.122]:54986 "EHLO ms-smtp-02.rdc-kc.rr.com") by vger.kernel.org with ESMTP id S265287AbUIOAUo (ORCPT ); Tue, 14 Sep 2004 20:20:44 -0400 Content-Disposition: inline In-Reply-To: <41473287.7050101@epita.fr>; from bevand_m@epita.fr on Tue, Sep 14, 2004 at 08:03:51PM +0200 List-Id: linux-ide@vger.kernel.org To: Marc Bevand Cc: linux-ide@vger.kernel.org Marc Bevand wrote: > [...] > An easy way to reproduce the problem is to run 4 instances of 'dd' reading > from 4 disks at the same time. It is much harder to reproduce when reading > from 3 disks, and quasi-impossible to reproduce when reading from 2 disks. I've tried, but cannot reproduce it here. System is: - Dual Xeon Dell Poweredge 2600 - Promise TX4 in 100MHz PCI-X slot. - 4 x Seagate ST3160023AS - 2.6.9-rc1 I've tried both dd and sg_utils, can't make it fail - no way, no how. > [...] > It seems the Promise chip has some problems under high-load conditions: > the throughput I obtain when reading from 4 disks is 100 MB/s (at 33MHz) > and 215 MB/s (at 66MHz)... I'm observing a lower throughput than that, though ~60MB/s; so I'm going to check to see if there is something else throttling performance, below the point of failure. -- andyw@pobox.com Andy Warner Voice: (612) 801-8549 Fax: (208) 575-5634