Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!know!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hpfcso!hpfinote!pnl From: pnl@hpfinote.HP.COM (Peter Lim) Newsgroups: comp.windows.ms Subject: Re: Floating point support? Message-ID: <18950044@hpfinote.HP.COM> Date: 8 Oct 90 19:47:58 GMT References: <1990Oct7.034814.25829@eng.umd.edu> Organization: Hewlett Packard CICD Lines: 40 > > It turns out that the 80386 handles most floating point math > pretty well all by itself, but the communication between > 80386-80387 is not so efficient. This is one of the reasons why the > 80486 incorporates the 80387 on chip. With previous generations of > Intel microprocessors, (80286, 808x) the math coprocessors (80287, > 8087) made a great difference because the processors weren't too > swift at floating point math. > This is not quite correct. The 8087 and 8088 is a great combination. Both CPU and interface speed is just right to give lots of improvement. The 80287 and 80286 is very bad combination. The CPU speed is substantially increase over the 8088 whereas the interface speed is not. In fact, for some application, 80287 actually SLOW DOWN the 80286 .... according to an old BYTE magazine. The 80387 and 80386 while not as well matched as the 8087 and 8088; is definitely much better matched than 80287 and 80286. All in all, it depends on the application you are running ? For most application, 80x87 will almost not help at all. For CAD, engineering simulation, FFT stuffs, the speed gain is very substantial. For spreadsheet, the speed gain is very mediocre; you'll be lucky to get double the speed. Another 2 cents' worth. Regards, ## Life is fast enough as it is ........ Peter Lim. ## .... DON'T PUSH IT !! >>>-------, ########################################### : E-mail: plim@hpsgwg.HP.COM Snail-mail: Hewlett Packard Singapore, : Tel: (065)-279-2289 (ICDS, ICS) | Telnet: 520-2289 1150 Depot Road, __\@/__ ... also at: pnl@hpfipnl.HP.COM Singapore 0410. SPLAT ! #include