Newsgroups: comp.sys.ibm.pc.hardware
Path: utzoo!utgpu!watserv1!maytag!looking!brad
From: brad@looking.on.ca (Brad Templeton)
Subject: Re: 386 Sx & 387 maths chip (16 Mhz) or 386/25 and no maths chip ??y
Organization: Looking Glass Software Ltd.
Date: Mon, 23 Jul 90 20:14:27 GMT
Message-ID: <1990Jul23.201427.14468@looking.on.ca>
References: <6585.26a7b1cc@vax1.tcd.ie> <90202.224428RFM@psuvm.psu.edu> <6499.26a985cd@uwovax.uwo.ca>

It's not an easy question...

- 387s are expensive, that's true.

- It is possible to write a very decent software math library for the
386, even in real mode, that uses the 32 bit registers.  You can get
acceptable FP performance for all but truly FP-intensive applications.
Some programs now do this, like my own 3-2-1 Blastoff.

- Most applications are still the stupid old DOS type, that do their
software FP with an 8087 emulator written with 16 bit register instructions.
S L O W.

- A 486 is cheaper than a 386+387.  If you plan for 387s from the start,
the 486 makes more sense, particularly because it is a lot faster at FP.

- The 486 may be cheaper, but the motherboards are not.  This is strictly
due to supply and demand, since in fact a 486 motherboard (with no cache,
no 387 socket, only 25 mhz parts) should be a fair bit cheaper than a
386 board.  Instead it costs twice as much.  Within a year the price of
these should drop.
-- 
Brad Templeton, ClariNet Communications Corp. -- Waterloo, Ontario 519/884-7473