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From: wilner@quill.DEC (Ken Wilner DTN 381-2388 ZK02-2/N59)
Newsgroups: net.invest
Subject: Tandem
Message-ID: <380@decwrl.UUCP>
Date: Tue, 29-Jan-85 16:51:07 EST
Article-I.D.: decwrl.380
Posted: Tue Jan 29 16:51:07 1985
Date-Received: Sat, 2-Feb-85 15:00:27 EST
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Organization: DEC Engineering Network
Lines: 43

>Newsgroups: net.invest
>Path: decwrl!decvax!bellcore!allegra!ulysses!mhuxr!mhuxj!houxm!hou2h!geopi
>Subject: Where is TNDM going?
>Posted: Wed Jan  2 12:17:44 1985


>Please, I am soliciting opinion, prognostications, clear visions,
>expert analysis, rumor, even idle talk concerning Tandem Computers'
>future in the fault-tolerant marketplace, and their capacity for
>continued growth, given their various emerging competition (Synapse, Stratus),
>and the announcement last year of the AT&T 3B20D.

>- George P. Cotsonas
>  AT&T Consumer Products Laboratories
>  Holmdel, New Jersey
>  ...houxm!hou2h!geopi


I used a Tandem NonStop system for about 1.5 years.  While conceptually a 
nice machine I did not really care for it.  The operating system was a real
pain to use, and the software in general was extremely hoggish.  In 
general, the only way to solve performance problems was to buy more memeory,
CPU's, and disk. This makes a relatively inexpensive system awfully 
expensive real quick. Hardware fault-tolerance seemed to work, but a few times
I saw the whole system crash.  Software fault-tolerance is acheived by 
checkpointing, is not user transparent, and must be debugged by crashing CPU's.
For any reasonably complex application it was practically impossible to 
implement correctly.  For all of the above reasons I would think longer 
and hard before I would be convinced that a Tandem system is the way to 
go. 


Although I am not intimately familar with them, it is my impression (possibly
incorrect) that all of the other vendors,  Stratus, Synapse, AT & T, and 
Sequoia (you forgot this one), provide software fault-tolerance transparently 
to the user.  This fact alone makes them more desireable than Tandem.  Tandem,
however, clearly has the advantage right now of market share, and that alone
may be enough to keep them on top for a very long time.


Ken Wilner

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