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Article #232

Re: Nat/Mot/Int; and DSI-32 optimizer

#232
From: John Gilmore
Date: Thu, 05 Dec 1985 10:17
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In article <120@utastro.UUCP>, jk@utastro.UUCP (John Krist) writes:
> I would like to see some talk about 32032 vs. 68020 vs. 80386 here in
> .16k land.  The people at Definicon say that the 68020 still has bugs
> and that Motorola's math processor doesn`t work well.  It seems that
> the 32032 is the most VAX-like.  Would this make it better for those
> surrounded by VAXen?

If you want the full story you should also read net.micro.68k and
net.arch, where these questions are being discussed (sometimes to
death).  The 68020 in the Sun-3 I'm typing on now has a few minor bugs,
but none that the compilers have to know about or that affect user
programs.  Last I heard, the National compilers have lots of hacks to avoid
instructions and sequences that tickle chip bugs.  (The worst of it is,
Motorola supplies a bug list to its customers, under nondisclosure;
National won't, and even took action against some of its own employees
who were telling customers about chip bugs.)

The 68881 math processor works fine and does nice 80-bit math in full
IEEE glory; the 16081 only does 64-bit math, and is much slower.

The 80386 looks like a serious contender to the 68020, though nobody I've
ever talked to, including people working on porting things to it, has
seen one.  (They use software simulators.)  When it is released, and
the operating system mods are done (not in the first release, I bet),
it will be able to run MS-DOS programs and such at the same time as
Unix -- which is a big win for many people.  On the other hand, I
bought the Sun-3 on the open market and got it a month ago and it runs
4.2BSD much faster than a Vax 780.  How long will it take to get a 4.3
port for the 386?

The 32032 is dead in this market; it's only 30% faster than a 16032,
which puts it right in the 68000 ballpark -- if you can get a bug-free
chip that runs at its rated clock speed.  (Haven't talked to anybody
who has seen one of those either.)  The 32332, well, it's faster than a
32032, but slower than both 68020 and 80386, so only people locked-in
to National chips will buy it.

I'd say the best micro for people who really like Vaxen is the microvax-2.


>        [DSI-32] WHETSTONE benchmark:
>            C: optimized - 4.11 sec
>               non-opt   - 4.40 sec
>          F77: optimized - 4.45 sec
>               non-opt   - 4.45 sec

Hmm, that's quite an optimizer.
Technical Details
Message-ID: <314@l5.uucp>
Path: arc1-ca.pugleaf.net!utzoo!linus!philabs!cmcl2!seismo!lll-crg!l5!gnu
References: <120@utastro.UUCP>

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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site l5.uucp
Path: arc1-ca.pugleaf.net!utzoo!linus!philabs!cmcl2!seismo!lll-crg!l5!gnu
From: gnu@l5.uucp (John Gilmore)
Newsgroups: net.micro.16k
Subject: Re: Nat/Mot/Int; and DSI-32 optimizer
Message-ID: <314@l5.uucp>
Date: Thu, 5-Dec-85 05:17:41 EST
Article-I.D.: l5.314
Posted: Thu Dec  5 05:17:41 1985
Date-Received: Sat, 7-Dec-85 15:48:29 EST
References: <120@utastro.UUCP>
Organization: Nebula Consultants in San Francisco
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