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From: preston@ariel.rice.edu (Preston Briggs)
Newsgroups: comp.arch
Subject: Re: Anything wrong with the i860
Message-ID: <1991May16.221437.10751@rice.edu>
Date: 16 May 91 22:14:37 GMT
References: <3486@charon.cwi.nl> <3986@ssc-bee.ssc-vax.UUCP> <dank.674423728@blacks>
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dank@blacks.jpl.nasa.gov (Dan Kegel) writes:

>I just ran a stupid benchmark (the FFT from Numerical Recipies, length 1024,
>2000 reps) on both a Sun 4/470 and an Alliant FX/2800.
>Performance was within 10% of identical.
>[Gee, everyone said the i860 was much faster than a Sun; 
>guess I misunderstood.]

The i860 can smoke a Sparc, but it takes a smart (mostly non-existant)
compiler and the right applications.  A man at Alliant charactarized
the 860 as having a small "sweet spot".

In early experiments (meaning primitive compilers), we measured a factor
of 21 improvement from (very tedious) hand coding and compiler results.

Basically, really advanced architectures require really advanced compilers
to get best results.  For example, vector machines need vectorizing
compilers.  The i860 needs many of the same techniques.

Preston Briggs