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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.mira.net.au!vic.news.telstra.net!act.news.telstra.net!psgrain!news.uoregon.edu!csulb.edu!info.ucla.edu!agate!howland.erols.net!www.nntp.primenet.com!nntp.primenet.com!enews.sgi.com!news.mathworks.com!newsfeed.internetmci.com!in2.uu.net!EU.net!usenet2.news.uk.psi.net!uknet!usenet1.news.uk.psi.net!uknet!dispatch.news.demon.net!demon!awfulhak.demon.co.uk!awfulhak.demon.co.uk!awfulhak.demon.c o.uk!not-for-mail From: brian@awfulhak.demon.co.uk (Brian Somers) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: SCSI card Date: 5 Sep 1996 17:22:28 +0100 Organization: Coverform Ltd. Lines: 49 Message-ID: <50muo4$a1@anorak.coverform.lan> References: <Pine.SOL.3.93.960903215141.13825B-100000@bmec.hscbklyn.edu> NNTP-Posting-Host: localhost.coverform.lan X-NNTP-Posting-Host: awfulhak.demon.co.uk X-Newsreader: TIN [version 1.2 PL2] David Zakai (zakaid99@hscbklyn.edu) wrote: : 1. Are there still significant incompatibilities when using : a PCI-based card (like Adaptec AHA-2940 or AHA-2920) instead : of ISA-based cards like Adaptec AVA-1522B ? I've just put my SCSI disks on a 2940W (instead of a 1542B). I'm getting occasional problems w/ the disks - nothing that a SCSI reset doesn't cure (the OS sends this after a bit of "disk timed out" complaining). I suspect that I'm just trying to drive the disks too fast, so I can't really complain about the OS itself. All my disks worked straight off on the 2940W - I didn't need to reformat anything. : 2. Is the performance boost significant for PCI versus ISA cards : (when PCI are double the cost) ? Yep. Mail me if you want actual figures - I've got lmbench output from my machine both before and after the upgrade. : 3. Is there a significant performance boost when using : bus mastering versus PIO (programmed IO) Adaptec cards? : (I don't think that I shall gain much advantage for tape : backup, but the Iomega JAZ drive has a Fast SCSI2 interface.) Is there such a thing as a non-bus-mastering SCSI card ? This matters more when you've got more than one user. : 4. If the computer's primary drive is an EIDE disk, can one : install a SCSI card with an onboard BIOS and boot from : an external bootable device like an Iomega JAZ drive ? : (I realize that one can use a boot manager on the primary : disk, but I would prefer to put the file system on the : external drive, so I would not neet to create FreeBSD : slices on the EIDE drive.) Depends on the SCSI controller - I believe some can boot "any" SCSI device. : The primary disk will probably have Win95. Oh well, I assume it's a necessary evil ! -- Brian <brian@awfulhak.demon.co.uk> Don't _EVER_ lose your sense of humour....