Path: utzoo!attcan!uunet!lll-winken!uwm.edu!rpi!uupsi!sunic!tut!funic!santra!santra!sja
From: sja@sirius.hut.fi (Sakari Jalovaara)
Newsgroups: comp.misc
Subject: Re: Exabyte (8mm) versus DAT (4mm)
Message-ID: <1990Jul12.164341.11429@santra.uucp>
Date: 12 Jul 90 17:43:10 GMT
References: <9007061713.AA01816@stc06.CTD.ORNL.GOV> <1881@proa.SV.DG.COM>
	<2188@dino.cs.iastate.edu>
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Organization: Helsinki University of Technology
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In-Reply-To: hascall@cs.iastate.edu's message of 10 Jul 90 01:37:32 GMT

We have an Exabyte and test-drove a WangDAT a couple of months ago
(neither worked too well on Suns with vanilla SunOS 4.0.3; 8mm seems
to work fine under SunOS 4.1, haven't tried DAT yet.)

> I've heard the 8mm are somewhat faster--does anyone have some real
> data on either of these?

A WangDAT manual says 183 kB/s sustained data rate; 8mm is the same
(I can't find the manual, I think it says 180 kB/s.)

We are being quoted prices that buy two WangDATs for the price of one
Exabyte.  Your mileage may vary.

Tapes appear to cost about the same (+/- 20%.)

8mm beats the DAT in storage capacity (something like 2GB vs 1.3GB
with max available tape lengths.)

DAT scores big points in that it seeks (skips files) much faster.  If
you have a full tape with 8 files, "mt fsf 8" takes *forever* on the
8mm, DAT does it in something like 30 sec worst-case (I can't find the
real timings in the manual.)

Drive & tape reliability and lifetime are the big questions.  Ask
again in a couple of years' time...
									++sja