Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!mips!winchester!mash
From: mash@mips.COM (John Mashey)
Newsgroups: comp.sys.super
Subject: Re: Cray vs. PC Benchmark
Message-ID: <42097@mips.mips.COM>
Date: 14 Oct 90 18:02:02 GMT
References: <38230@ut-emx.uucp>
Sender: news@mips.COM
Reply-To: mash@mips.COM (John Mashey)
Organization: MIPS Computer Systems, Inc.
Lines: 24

In article <38230@ut-emx.uucp> ddt@ccwf.cc.utexas.edu (David Taylor) writes:
>In article <161512.23931@timbuk.cray.com> ds@juniper09.cray.com (David Sielaff) writes:
>>In article <1990Oct9.192119.4453@murdoch.acc.Virginia.EDU> clc5q@shamash.cs.Virginia.EDU (Clark L. Coleman) writes:
>
>>>I realize that Dhrystones are not meaningful for supercomputer applications,
>>>but I thought that the scalar integer MIPS of a Cray would still exceed a
>>>PC.
Dhrystone is not geenrally meaningful these days, period.
It is well-known that compiler hacks exist (around the strcpy call),
that can boost apparent performance 30-40%, without affecting real programs
in any noticable fashion.  IT almost always overstates performance relative
to a VAX, which is why it is so popular among some computer companies :-)
...
>Understatement of the year.  SPEC is the closest that comes to the
>"whole truth", and even it is pretty far from the mark (bad pun).
SPEC as it sits, is hardly close to "the whole truth", and of course
didn't intend to be.  I'd be very suspicious of anything that claimed to
be the whole truth, as opposed to a better approximation to reality.
For supercomputers, Perfect Club probably tells you more.
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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