Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!crdgw1!sixhub!davidsen
From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Cyrix CX-803D87-20 Coprocessor
Message-ID: <1969@sixhub.UUCP>
Date: 29 Sep 90 21:58:03 GMT
References: <14244@shlump.nac.dec.com> <1990Aug4.220844.7349@water.waterloo.edu> <128@thor.UUCP> <1990Sep27.060417.23408@agate.berkeley.edu>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 21

In article <1990Sep27.060417.23408@agate.berkeley.edu> ilan343@violet.berkeley.edu writes:

| I have seen adds for Cyrix FastMath coprocessor (80387 compatible) that
| claims 3X speedups.  Are there any benchmarks to support this?
| Also, is compatibility an issue?

  I believe that was at 25MHz, but not 33MHz. Intel seems to have
changed the mask in the 33MHz version, so that it is faster by a good
bit. I believe several tests have shown this, including the recent one
in either _PC Week_ or _Info World_. I have been told that putting the
33MHz version in a 25MHz system will be about 40% faster, due to some
instructions taking fewer cycles. The people who told me this believed
it enough to buy the fa$ter part.

  This may be the only case where putting in a faster *rated* part
actually made the system faster without changing the operating speed.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me