Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: 386 Clones
Message-ID: <2816@crdos1.crd.ge.COM>
Date: 31 Oct 90 13:19:21 GMT
References: <10833@pt.cs.cmu.edu> <35204@cup.portal.com> <2790@crdos1.crd.ge.COM> <1990Oct26.015244.586@amd.com> <8464@scolex.sco.COM>
Reply-To: davidsen@crdos1.crd.ge.com (bill davidsen)
Organization: GE Corp R&D Center, Schenectady NY
Lines: 33

In article <8464@scolex.sco.COM> seanf (Sean Fagan) writes:

| Well... the Cyrix '387 clones are pin compatable, are *much* faster than the
| '387.  From what I've read of the cycle counts for the Cyrix chip and the
| '486, the Cyrix is faster than the "487" as well.  (Unfortunately, you have
| to use it in "memory mapped" mode, a la Weitek, because of the way the '486
| was designed.)

  If I were in the business of producing niche products, I would be
highly tempted to build a board with several of these chips, a DMA
interface, some memory for workspace and status, and call it a vector
unit.

  If I had a lot of time I would hack a compiler like gcc to produce
code for it, but since Cray and Convex users are willing to do
operations by calling subroutines, I would probably code up a set of
subroutines in assembler to deal with this. I suspect that a board with
three FPUs would cost <$2k to build and market, and could sell for $5k.

  The market would be MS-DOS and 386ix users who wanted to use FORTRAN
and stay in a PC environment, but have better than workstation
performance with IEEE results.

  At the time I looked at this (several years ago) there were a few
boards in this market, I'm not sure they were shipping, and I don't
believe they were IEEE.

  I suspect you could do the same thing with the 860 and get better
performance, but I am not sure the cost could be kept low enough for
this market, nor that there is a market one price step higher ($10-15k).
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
       The Twin Peaks Haloween costume: stark naked in a body bag