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From: johnl@ima.ISC.COM (John R. Levine)
Newsgroups: comp.arch
Subject: Re: D-machine helped spawn RISC
Message-ID: <709@ima.ISC.COM>
Date: Wed, 16-Sep-87 14:35:30 EDT
Article-I.D.: ima.709
Posted: Wed Sep 16 14:35:30 1987
Date-Received: Sat, 19-Sep-87 02:13:16 EDT
References: <4782@sdcrdcf.UUCP> <475@esunix.UUCP> <347@erc3ba.UUCP>
Reply-To: johnl@ima.UUCP (John R. Levine)
Organization: Not enough to make any difference
Lines: 30
Keywords: VLIW Multiflow

In article <347@erc3ba.UUCP> sd@erc3ba.UUCP (S.Davidson) writes:
>[Horizontal microcode RISC machines have]
>happened already, though they are not all the rage yet.  They are
>called Very Long Instruction Word machines, and one of the originators,
>Josh Fisher, did his dissertation on global compaction of horizontal
>microcode.  Josh moved to Yale after he graduated, and then moved to a
>company to build a VLIW machine.  ...

Josh's company, Multiflow Computer, is shipping their smallest minisuper,
the Trace 7/200.  It runs real fast, e.g. LINPACK 6.0 mflops compared to,
say, an IBM 3090-200's 6.8 mflops, which is not bad for a machine that
costs $300K.  According to people I know there, it turned out to run faster
than they projected it to, and in some customer benchmarks outperformed a
Cray X/MP.

The Trace 7 has a 256 bit instruction word, they're working on 512 bit and
1024 bit versions.  Unlike most other minisupers, there is no vector
processing hardware.  It executes one enormous instruction at a time, and
there is considerable compiler cleverness involved in getting as much useful
work as possible done in a single enormous instruction.  Not using vectors
means that existing cruddy Fortran code can be compiled effectively without
having to rework it to make it more easily parallelizable.

[Disclaimer:  No connection to Multiflow except that I know a lot of the
people who work there.]
-- 
John R. Levine, Cambridge MA, +1 617 492 3869
{ ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something
The Iran-Contra affair:  None of this would have happened if Ronald Reagan
were still alive.