[comp.windows.ms] Floating point for windows??

i1neal@exnet.iastate.edu (Neal Rauhauser -- ELT Computer Applications Group) (01/08/91)

    Does windows use a floating point chip if its present? I have no
programs that specifically require one, but $300 for a 387sx would
be much easier to take than upgrading my sx to a full size machine.
I'd like to here from someone who has done a side by side comparison
of two identical machines except that one has a 387. I'll post
results if they're interesting enough

   Neal i1neal@exnet.iastate.edu

burgoyne@eng.umd.edu (John R. Burgoyne) (01/08/91)

In article <1991Jan7.164119.10490@news.iastate.edu> i1neal@exnet.iastate.edu (Neal Rauhauser -- ELT Computer Applications Group) writes:
>
>
>    Does windows use a floating point chip if its present? I have no
>programs that specifically require one, but $300 for a 387sx would
>be much easier to take than upgrading my sx to a full size machine.
>I'd like to here from someone who has done a side by side comparison
>of two identical machines except that one has a 387. I'll post
>results if they're interesting enough
>
>   Neal i1neal@exnet.iastate.edu

This thread went through the group last fall. The bottom line is that
interprocess comm. between the 386 and 387 is not that efficient, but the
386 by itself doesn't do badly for arithmetic. Thus, there is almost
no improvement until you do trig or transcendental math. Some functions
might execute in say 10 clock cycles with a 387 but 80 with a 386 only.
So unless you have a loop of a large number of such equations, I'm
not confident you'll notice.

BYTE or PC Magazine did this test sometime last year. I'll look for
the article date or perhaps someone else already knows.

Robert

poffen@sj.ate.slb.com (Russ Poffenberger) (01/09/91)

In article <1991Jan7.164119.10490@news.iastate.edu> i1neal@exnet.iastate.edu (Neal Rauhauser -- ELT Computer Applications Group) writes:
>
>
>    Does windows use a floating point chip if its present? I have no
>programs that specifically require one, but $300 for a 387sx would
>be much easier to take than upgrading my sx to a full size machine.
>I'd like to here from someone who has done a side by side comparison
>of two identical machines except that one has a 387. I'll post
>results if they're interesting enough
>

If I am not mistaken, Windows uses integers internally, so, no, a floating
point chip wouldn't help.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
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uchuck@pelham.med.unc.edu (Charles Bennett) (01/10/91)

This brings up another question.  I notice that a program "win87em" is in
memory while running Windows 3.0.  This is a .DLL in the \SYSTEM
subdirectory.  My assumption (I know, I know) is that it _could_ be a
80x87 software emulator.  I have a real "in-the flesh" 387 coprocessor on
board and the "About" box in Excel knows about it.  So WHY do I need an
emulator, if indeed that is what it is???

  Chuck Bennett                               INTERNET: uchuck@med.unc.edu
  Medical Sciences Teaching Labs              BITNET:   uchuck@unc
  CB# 7520  University of NC                  PHONE:    919-966-1134(w)
  Chapel Hill, NC  27599-7520