Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!orion.oac.uci.edu!sfrank
From: sfrank@orion.oac.uci.edu (Steven Frank)
Newsgroups: comp.periphs.scsi
Subject: Re: DAT versus 8mm Tape
Message-ID: <27388281.13536@orion.oac.uci.edu>
Date: 7 Nov 90 21:54:08 GMT
References: <272DB1E1.9737@orion.oac.uci.edu> <kusumoto.657844687@chsun1> <tim.657856065@gumby>
Reply-To: steve@fisher.bio.uci.edu (Steven Frank)
Organization: University of California, Irvine
Lines: 71

Several people requested a summary of the 8mm versus Tape debate:

1.  All 8mm units are currently made by Exabyte, although other 
    manufacturers package the drive.  The current model that is 
    available is the EXB8200, which holds 2.3 GB per tape.  Each
    tape costs about $7.  This model is available from anDATAco
    for $2400.  Call (800) 334-9191.  

2.  The 8mm EXB8200 has a very slow seek time.   A new model available
    next month, EXB8200-SX will have a seek time comparable to DATs
    (so they say).  The new drive has a chip that counts servo pulses.
    How well it works in practice is not known (eg, drivers, etc).
    The new model is about $3000.  Finally, a EXB8500 will be out
    soon that has fast seek and holds 5 GB per tape.

3.  People using the Exabytes are uniformly pleased with performance, etc,
    but of course do not use the machines for anything other than dumps
    since the seek times are slow.  Also, the drives apparently need
    to be cleaned about every 30 hours of use, and cleaning does
    affect performance.

4.  Many people are very enthusiastic about DATs.  Since DATs are new
    not surprisingly most responses are from people associated with 
    manufacturers.  Some facts:  (a) current DATs hold 1.3 GB per tape;
    (b) seek times are relatively fast, 20-40 seconds for any file
    on a tape.

5.  Some articles about DATs:  (a) IEEE Spectrum, Oct 1989, (b) Nov Byte;
    (c) SunTech journal ??

6.  Some advantages claimed for DATs relative to 8mm: (a) DAT is digital
    whereas 8mm is an analogue medium (why this is a big advantage isn't
    clear, beyond obvious fact that data from hard disks are digital);
    (b) DATs are cheaper; (c) DATs are self-cleaning; (d) DATs are the
    tape drive of the future, so prices will continue to drop;  (e) fast
    seek is easier to implement for DATs because of the mechanics of 
    read/write and storage; (f) DATs have enthusiasm of many vendors.
    (g) future DATs will have higher capacities than 8mm..

7.  My current impression of the claimed advantages in 6:
    (a) I don't know???
    (b) I have prices only for Hewlett-Packard DATs (street prices).
        The 35450-67905 is $1925 from Lex Electronics (714) 587-0404.
    (c) Seems to be true
    (d) Hard to judge.  Many manufacturers are selling or developing
        DATs.  Apparently they can and will soon be made in 3.5" form
        factor, and will be pushed in the PC and MAC market.  Acceptance
        in these markets guarantees lower prices, more competition
        and more variation in product quality, with the best being 
        very good.
    (e) Appears to be true, although new Exabytes are said to be just
        as fast although more expensive.
    (f) True
    (g) HP has announced a 2 GB 3.5" DAT (35470) and a similar drive
        with hardware compression (8 GB with compression).  8mm is 
        near releasing 5 GB drives.  My guess is that DATs may be 
        behind here, but price per GB may soon favor DATs. (The new
        HP drives will not be available for 6 to 9 months).

8.  Overall, it is a toss-up at present.  The future does seem to favor
    DATs, but that is hard to predict.  

9.  REQUEST:  Please send model numbers, street prices and vendor names and
    phone numbers for DAT drives.  Many claim that DATs are cheaper, but
    actual prices and vendors are needed by those of us considering a 
    purchase.

Thanks,

steve frank
steve@fisher.bio.uci.edu