From owner-freebsd-scsi Fri Oct 15 12:11:22 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from chuggalug.clues.com (chuggalug.clues.com [194.217.82.22]) by hub.freebsd.org (Postfix) with ESMTP id 46018153A4 for ; Fri, 15 Oct 1999 12:11:17 -0700 (PDT) (envelope-from geoffb@chuggalug.clues.com) Received: (from geoffb@localhost) by chuggalug.clues.com (8.9.3/8.9.3) id UAA57256; Fri, 15 Oct 1999 20:11:03 +0100 (BST) (envelope-from geoffb) Date: Fri, 15 Oct 1999 20:11:03 +0100 From: Geoff Buckingham To: Matthew Jacob Cc: Andrew Gallatin , "Kenneth D. Merry" , scsi@FreeBSD.ORG Subject: Re: FreeBSD 3.2 / Slow SCSI Dell PowerEdge 4300 Message-ID: <19991015201103.B56536@chuggalug.clues.com> References: <14343.16009.738375.608477@grasshopper.cs.duke.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: ; from Matthew Jacob on Fri, Oct 15, 1999 at 09:01:38AM -0700 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > > On Fri, 15 Oct 1999, Andrew Gallatin wrote: > > > > > Geoff Buckingham writes: > > > On Thu, Oct 14, 1999 at 04:55:45PM -0600, Kenneth D. Merry wrote: > > > > > > > > Western Digital drives generally aren't that great. In fact, we have > > > > disabled tagged queueing for most all Western Digital SCSI drives. > > > > (including the drives you have, above) > > > > > > > > > > I have been meaning to post on this subject for some time, while in my last > > > place of employment I bought 8 Dell PowerEdge 2300s each with six drives > > > Dell supplied Western digitals and I had really poor disk performance. > > > > > > I realised tagged queing was disabled for WDE* and removed the quirk from > > > cam_xpt.c this greatly improved the performance. Much exercising of the disks > > > also failed to cause any further problems. > > > > I'm the guy to blame for this quirk. My drives (shipped in about 60 > > older Dell Dimension XPS D300 here) have abysmal sequential write > > performance with tagged queuing enabled. There are two types of > > identifiers: > > > > pass0: Fixed Direct Access SCSI-2 device > > pass0: Serial Number WS7010610507 > > pass0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > > > > pass1: Fixed Direct Access SCSI-2 device > > pass1: Serial Number WS7011244369 > > pass1: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > > > > >From the reports I've seen, it looks like Western Digital got their > > act together and their Ultra2 drives are OK. Could we make the quirk > > entry enable tagged queuing for Ultra2 WDE drives & disable it for > > non-ultra2 drives? I just got this from a former colleage, details of the drives we had: da4 at ahc0 bus 0 target 4 lun 0 da4: Fixed Direct Access SCSI-2 device da4: 80.000MB/s transfers (40.000MHz, offset 31, 16bit) da4: 8687MB (17793001 512 byte sectors: 255H 63S/T 1107C) In my opinion these do not require the quirk. (based on bonnie results for individual disks with WCE as shipped (off i think) you get better sequential performance and more importantly for most of us better seeking) -- GeoffB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message