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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!news.unimelb.EDU.AU!munnari.OZ.AU!spool.mu.edu!howland.erols.net!worldnet.att.net!newsxfer2.itd.umich.edu!uunet!in3.uu.net!198.82.160.249!solaris.cc.vt.edu!csugrad.cs.vt.edu!csugrad.cs.vt.edu!not-for-mail From: jaitken@csugrad.cs.vt.edu (Jeff Aitken) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Seeking advice on new system purchase Date: 25 Dec 1996 08:19:06 -0500 Organization: Virginia Tech Computer Science Dept, Blacksburg, VA Lines: 46 Message-ID: <59r9ka$m4f@csugrad.cs.vt.edu> References: <59dhb9$p6g@shellx.best.com> NNTP-Posting-Host: csugrad.cs.vt.edu X-Newsreader: TIN [version 1.2 PL2] Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:33110 Tony Porczyk (tporczyk@best.com) wrote: : 3. Within a foreseable future I would like to add a SCSI tape and : perhaps even a writeable CDROM (primarily for use with another OS). : Would Adaptec 3940 be appropriate for such a task? (to split the : primary hard drive from tape and CD). Or would it be better to buy : two separate 2940s? Am I misunderstanding the purpose of 3940? There's no reason (given the situation you've described) to have more than one SCSI controller in this system. Actual numbers vary from OS to OS, but you can generally have about four SCSI disk drives on a single controller before the SCSI bus becomes the bottleneck (*). Also, a tape drive doesn't really count because it's (a) much slower than, and (b) accessed much less frequently than your disk drives. So if you get two SCSI controllers and put a disk or two on one and a tape & CDROM on the other, both will sit idle most of the time. Unless I had money to burn, I'd go with a single 2940. My next upgrade would be to both a UW controller and UW peripherals (**), because that increases the speed of the slowest component in your system -- the disk drive(s). (*) With a good controller and device driver implementation, of course! :-) I don't own an AIC-based board, but from all I've heard both the controllers and the FreeBSD drivers for them are top-notch. (**) Those damn Seagate Barracuda's are *very* nice drives, and f-a-s-t too. I don't know anything about the IBM drives you mentioned, but I can say that the Barracuda line of drives is well worth the extra $$$. : 5. For the type of use I have described, does it make much of a : difference to go to UW for SCSI? See above. If you've got the money, I'd spend it here before going with a dual-controller SCSI system. You can always add another SCSI card later, or replace it with the 3940. Oh, one last thing. AFAIK, the 3940 is functionally equivalent to a pair of 2940's. If you decide you really need two independent SCSI controllers, I think you can use a 3940 and save yourself a (precious) PCI slot. -- Jeff Aitken jaitken@dimension.net