Path: utzoo!attcan!uunet!husc6!mailrus!ames!amdahl!pyramid!prls!mips!mash
From: mash@mips.COM (John Mashey)
Newsgroups: comp.arch
Subject: Re: The VAX Always Uses Fewer Instructions
Keywords: VAX MIPS
Message-ID: <2476@winchester.mips.COM>
Date: 30 Jun 88 08:11:04 GMT
References: <6921@cit-vax.Caltech.Edu> <28200161@urbsdc> <10595@sol.ARPA> <914@entropy.ms.washington.edu> <12179@mimsy.UUCP>
Reply-To: mash@winchester.UUCP (John Mashey)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 29

In article <12179@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
...
>Who cares about the arguments?  The fact is that if you have somewhere
>between $10,000 and $1,000,000, and want to buy the fastest machine you
>can get for that, right now that machine is probably `RISC-based'.
>
>You can argue all you like as to why the Vax instruction set is better,
>or why the 88000 instruction set is better, but the fastest Vax CPU from
>DEC is slower than the fastest 88000 CPU from Motorola.
--------^^^^^^

On what set of benchmarks is this assertion based?
(I believe it's true for integer and single-precision FP, and if you'd
said MIPS, it would have been true for DP floating also :-)
So far, the only double-precision floating-point number we've seen
for the 88K is Whetstone: 3 Megawhets (and I don't remember the source,
sorry). (An 8700 is about 4Mwhets DP).  We'd be VERY interested to
see more DP benchmarks: from an examination of the 88K's architecture
and the cycle counts, we have reasons to believe that the 88K
design essentially SACRIFIED double precision floating performance for
most compiled programs.  We'd be glad to be disabused by knowledgable folks
who can cite useful benchmarks like: DP Livermore Loops, Spice, Doduc, etc.
Note one more time that VAX-relative performance numbers, computed the
way DEC does, includes floating point.....
-- 
-john mashey	DISCLAIMER: 
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