From owner-freebsd-current@FreeBSD.ORG Tue Apr 17 15:30:10 2007 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id EF6C616A400; Tue, 17 Apr 2007 15:30:10 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id 895C513C480; Tue, 17 Apr 2007 15:30:10 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from phobos.samsco.home (phobos.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.13.8/8.13.8) with ESMTP id l3HFU7sH032163; Tue, 17 Apr 2007 09:30:07 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <4624E7F3.203@samsco.org> Date: Tue, 17 Apr 2007 09:29:55 -0600 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.2pre) Gecko/20070111 SeaMonkey/1.1 MIME-Version: 1.0 To: Kris Kennaway References: <200704162247.29909.gelsemap@superhero.nl> <20070416230322.GA69661@xor.obsecurity.org> <49836.195.50.100.20.1176808326.squirrel@www.superhero.nl> <20070417151829.GA1252@xor.obsecurity.org> In-Reply-To: <20070417151829.GA1252@xor.obsecurity.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (pooker.samsco.org [168.103.85.57]); Tue, 17 Apr 2007 09:30:07 -0600 (MDT) X-Spam-Status: No, score=-1.4 required=5.5 tests=ALL_TRUSTED autolearn=failed version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on pooker.samsco.org Cc: freebsd-current@freebsd.org, "Gelsema, P \(Patrick\) - FreeBSD" , freebsd-hardware@freebsd.org Subject: Re: Difference between 6.2 and 7.0 Adaptec 39320D - 7.0 performing less X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Apr 2007 15:30:11 -0000 Kris Kennaway wrote: > On Tue, Apr 17, 2007 at 01:12:06PM +0200, Gelsema, P (Patrick) - FreeBSD wrote: >> On Tue, April 17, 2007 01:03, Kris Kennaway wrote: >>> On Mon, Apr 16, 2007 at 10:47:24PM +0200, Gelsema, P (Patrick) wrote: >>>> Goodevening lists, >>>> >>>> I am toying with Freebsd 7 to see if it will and how it runs on my new >>>> Asus >>>> M2N mainboard. One of the things I noticed is that when running >>>> 7.0-Current-200704 the throughput of the SCSI drive seems halved. When >>>> running 6.2 throughput is doubled/normal. >>>> >>>> Throughput is measured with the following command. >>>> >>>> dd if=/dev/zero of=/usr/test >>>> where /usr resides on da0s1f >>>> >>>> On 7.0 I get about 33MB/sec >>>> On 6.2 I get about 69Mb/sec >>>> >>>> I did not make any changes, installation is fresh from CD with Minimal >>>> as >>>> distribution. >>> Apparently you weren't paying attention during boot, because 7.0 ships >>> with heavy debugging options enabled, and tells you about it up front: >>> >>> "WARNING: WITNESS option enabled, expect reduced performance.\n"; >>> >>> Recompile your kernel with debugging options disabled before making >>> performance comparisons. >>> >>> Kris >>> >> Ok, what you are saying makes sense. I did see the warnings and the bits >> in the kernel config. The thing that triggered me was that when paying >> attention during boot the SCSI Disk was detected as only 160.00MB/s >> instead of the expected 320.00MB/s. The detection of devices is not >> subject to debugging, is it? > > Someone else pointed this out to me, to be honest I didn't get that > far in your email after noticing the big blunder of leaving debugging > enabled :) > > I agree that the different speed negotiation is a likely potential > cause of poor performance as well, but it really doesn't make sense to > be making performance comparisons when one system has all possible > debugging enabled and the other has no debugging enabled. > > Kris The difference in bus speed is hardly perceptible for a single target. U320 does reduce the per-command latency by a good deal, but for large I/O transfers it'll mostly be in the noise. Scott