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From: sambo@ukma.uky.csnet (Father of micro-ln)
Newsgroups: net.micro.pc
Subject: Re: 80287 and the IBM AT
Message-ID: <4363@ukma.uky.csnet>
Date: Fri, 12-Sep-86 01:22:07 EDT
Article-I.D.: ukma.4363
Posted: Fri Sep 12 01:22:07 1986
Date-Received: Sat, 13-Sep-86 21:21:20 EDT
References: <3312@utcsri.UUCP> <253@psueea.UUCP>
Distribution: net
Organization: U of Kentucky, Mathematical Sciences, Lexington KY
Lines: 26
Summary: Quick reading of BYTE article can lead to wrong conclusions

In article <253@psueea.UUCP> waldref@psueea.UUCP (Greg Waldref) writes:
>Depending on what you are using, putting a 287 may not get you
>anywhere.  In fact, it may slow down your system!
>     
>You may want to check the IBM special issue (10/85) of Byte, page 66 on.
>the benchmarks that they ran did not give the increase in proformence
>that you might expect.  In at least one case it slowed it down.

As I recall, the impression I got when I first read the article mentioned
above was different than the impression I got upon the second reading.
Now that I have reread the article quickly, I am not convinced the author
was comparing apples with apples when he stated the 80287 can degrade a
PC's performance.  Sure, it is possible to construe cases in which this is
true: run the 80286 at 10 MHz and the 80287 at 2 MHz, or write some software
that uses the 80287 to move floating-point numbers from one memory location
to another without change in format, as opposed to using the 80286 to do the
same.  *I* (though maybe not you) think the main point being made was that
the 80287 might provide marginal speedup at best in some cases, and if one is
not real careful to do things right, it may actually hinder performance.  (I
guess my only quibble with Mr. Waldref's article is the last sentence quoted
above.)
-- 
Samuel A. Figueroa, Dept. of CS, Univ. of KY, Lexington, KY  40506-0027
UUCP: cbosgd!ukma!sambo    CSNET: sambo@uky.csnet

	"Micro-ln is great, if only people would start using it."