Path: utzoo!attcan!uunet!lll-winken!csd4.milw.wisc.edu!bionet!ames!vsi1!daver!mips!mash
From: mash@mips.COM (John Mashey)
Newsgroups: comp.arch
Subject: Re: i860 Dhrystones
Keywords: i860 N10 Floating Point Dhrystones
Message-ID: <15475@winchester.mips.COM>
Date: 18 Mar 89 07:47:52 GMT
References: <39388@oliveb.olivetti.com>
Reply-To: mash@mips.COM (John Mashey)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 45

In article <39388@oliveb.olivetti.com> chase@Ricerca.UUCP (David Chase) writes:
>In article <955@masscomp.UUCP> hanko@masscomp.UUCP (Jim Hanko) writes:
....
>>I think it would clearly be unfair to compare Dhrystone numbers where this
>>trick was used to those where a strcpy subroutine was called. 
...
>Get real.  Nobody with a half a brain should trust silly little
>benchmark programs that reduce performance to a single number.
>Develop benchmarks based on real code that does real work, and perhaps
>compiler writers will target will target all those "unfair"
>optimizations at code that people actually use.  Procedure inlining is
>"not in the spirit of Dhrystone", but it would be stupid not to use it
>for real programs if it was reasonably implemented.
>
>When I want to compare processors, I run the programs that I use every
>day.  The one that works best on those is the one that works best for me.

A lot of us do this, and we also try to publish it.
So far, Intel:
	-published the results of EXACTLY ONE integer benchmark (Dhrystone
	1.1 & 2.1) actually measured on this machine (@ 33MHz)
	-features this number prominently in its marketing claims
	(well, actually, it features the numbers that would be gotten at 40MHz,
	or sometimes 50MHz)
	-uses it frequently to claim superiority over other processors
	-in its performance document, describes Dhrystone WITHOUT THE SLIGHTEST
	TRACE OF CAVEATS about the care with which these results must be
	interpreted, despite the fact that the Dhrystone sources give such
	caveats, and that the Dhrystone table in the Intel document comes
	straight from a document that takes great pains to warn the reader
	to be very careful about interpretation.

However, Olivetti is not Intel.  Since you work at a site well-known to be
working on i860s, perhaps you could suggest for us the "programs that you
use every day" that you run on an i860, and performance thereof,
so we could have a better shot at evaluating its performance.  You could
really help the cause of realistic-benchmarking by posting
sources-of-real-programs (if any could be public domain) of such programs
and their i860 times.....  Anyway, it's no wonder than many users of
computers trust vendors abotu as far as they can throw them....
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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