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From: gas@lanl.ARPA
Newsgroups: net.arch
Subject: Re: Scientific Computing and mips
Message-ID: <30105@lanl.ARPA>
Date: Sun, 25-Aug-85 00:02:41 EDT
Article-I.D.: lanl.30105
Posted: Sun Aug 25 00:02:41 1985
Date-Received: Tue, 27-Aug-85 01:13:29 EDT
References: <419@kontron.UUCP> <2300001@uicsl> <1093@ames.UUCP> <29898@lanl.ARPA> <1517@peora.UUCP>
Organization: Los Alamos National Laboratory
Lines: 27

> > It helps draw the line between special purpose and general purpose
> > environments (or, less tactfully, usable and unusable machines)..
>
> I assume you mean "special purpose" environments are "usable" whereas
> "general purpose" ones are "unusable"... what properties of general purpose
> environments make them "unusable" for scientific/engineering computing?

Sorry the statement was not crystal clear - the observation is that MIPS
measurements provide a microscopic view of machine performance that is
open to interpretation and is less desirable than benchmarks that are
far too large to permit hand optimization and tuning.  Artistic issues aside,
what will determine success is market share, and the way to gain market
share and credibility in the scientific/engineering market is with this
type of benchmark (MSC/Nastran).  It's my belief that this market requires
"general purpose architectures" with "general purpose (usable) environments"
(or else you have no hope of even compiling and loading the code, where the
full load map can exceed 50,000 lines alone).  

I don't think a special purpose architecture (e.g. an ap) can
provide an "easily used" environment, and is therefore at a severe 
disadvantage in the market.  My caution to architects is not to be myopic
when approaching performance measurement.  Respected benchmarks do
exist for the engineering and scientific marketplace.  These codes determine
raw machine performance and the likelyhood that the typical user will see
that benefit.         george spix       gas@lanl

(if the factorial of 0 is 1, is uncertainty certain?)