Date: Fri, 15 Oct 1999 20:11:03 +0100 From: Geoff Buckingham <geoffb@chuggalug.clues.com> To: Matthew Jacob <mjacob@feral.com> Cc: Andrew Gallatin <gallatin@cs.duke.edu>, "Kenneth D. Merry" <ken@kdm.org>, scsi@FreeBSD.ORG Subject: Re: FreeBSD 3.2 / Slow SCSI Dell PowerEdge 4300 Message-ID: <19991015201103.B56536@chuggalug.clues.com> In-Reply-To: <Pine.BSF.4.05.9910150901250.6773-100000@semuta.feral.com>; from Matthew Jacob on Fri, Oct 15, 1999 at 09:01:38AM -0700 References: <14343.16009.738375.608477@grasshopper.cs.duke.edu> <Pine.BSF.4.05.9910150901250.6773-100000@semuta.feral.com>
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> > > 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: <WDIGTL WDE4360-1807A3 1.80> Fixed Direct Access SCSI-2 device > > pass0: Serial Number WS7010610507 > > pass0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > > > > pass1: <WDIGTL ENTERPRISE 1.91> 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: <WDIGTL WDE9180 ULTRA2 1.20> 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
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