Date: Sun, 21 Feb 1999 16:01:53 -0700 (MST) From: "Kenneth D. Merry" <ken@plutotech.com> To: jmz@FreeBSD.ORG (Jean-Marc Zucconi) Cc: scsi@FreeBSD.ORG Subject: Re: LVD transfer rate Message-ID: <199902212301.QAA21624@panzer.plutotech.com> In-Reply-To: <199902212255.XAA73327@qix> from Jean-Marc Zucconi at "Feb 21, 1999 11:55:44 pm"
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Jean-Marc Zucconi wrote... > >>>>> Kenneth D Merry writes: > > > Jean-Marc Zucconi wrote... > >> I just installed a LVD drive and the boot message reports only 40MB/s > >> transfer rate. I expected 80MB/s - did I something wrong ? > >> > >> da1: <IBM DDRS-39130D DC1B> Fixed Direct Access SCSI-2 device > >> da1: Serial Number RE205733 > >> da1: 40.000MB/s transfers (20.000MHz, offset 15, 16bit), Tagged Queueing Enabled > >> da1: 8715MB (17850000 512 byte sectors: 255H 63S/T 1111C) > >> > >> This is the only device on the LVD bus (Adaptec controller on a Asus > >> P2BDS). I also have drives on the 50pin connector, but this should not > >> be the problem ? > > > There are several things to check: > > > - some drives have a single-ended-only jumper. You should make sure the > > jumper settings are correct for LVD operation. > > I have a jumper labelled `SE mode', and this jumper is ON, however the > drive does not work if I remove the jumper: the drive appears in the > SCSIselect utility, but it does not reports its capacity, and trying > to format fails (Not ready, asc/ascq= 40/80). That jumper forces it into Single Ended mode. What kind of cable do you have? LVD drives don't have internal terminators. You need an LVD cable (one of the "twisty" 68-pin cables) with a terminator block on the end. > > - make sure there aren't any settings in the SCSI BIOS that would prevent > > things from going at LVD speeds. > > It is set to 80MB/s Good. > > I seriously doubt this is your problem, but I've got a machine at work with > > two 18G Seagate Cheetah II's on a Super Micro motherboard with an onboard > > 7890. The problem is that the drives are SCA, and the SCA to 68-pin > > converters we put on them apparantly inhibit LVD. So they only run at > > 20MHz instead of 40MHz. > > No - connectors and cables are standard (80pins) You have SCA disks? Is the cable terminated? Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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