From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: Performance figure for sx8 driver Date: Thu, 09 Jun 2005 02:09:28 -0400 Message-ID: <42A7DD18.50004@pobox.com> References: <20050608212425.8951j70kxbwpcs8c@www.nucleodyne.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:28372 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S262280AbVFIGJb (ORCPT ); Thu, 9 Jun 2005 02:09:31 -0400 In-Reply-To: <20050608212425.8951j70kxbwpcs8c@www.nucleodyne.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: kallol@nucleodyne.com Cc: linux-kernel@vger.kernel.org, "linux-ide@vger.kernel.org" kallol@nucleodyne.com wrote: > Does anyone have performace figure for sx8 driver which is for promise SATAII150 > 8 port PCI-X adapter? > > Someone reports that on a platform with sx8 driver, multiple hdparms on > different disks those are connected to the same adapter (there are 8 ports) can > not get more than 45MB/sec in total, whereas a SCSI based driver for the same > adapter gets around 150MB/sec. > > Any comment on this? Known. Early firmwares for SX8 had problems that forced the driver to limit the number of outstanding requests, for all ports, to _one_. Later firmwares have fixed this, but the driver has not been updated to detect newer(fixed) firmwares. You may update drivers/block/sx8.c as such: - CARM_MAX_Q = 1, /* one command at a time */ + CARM_MAX_Q = 30, /* 30 commands at a time */ if you have a newer firmware, to obtain much better performance. Jeff