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From: tuba@ur-tut.UUCP (Jon Krueger)
Newsgroups: net.arch
Subject: Re: Mips / MHz
Message-ID: <332@ur-tut.UUCP>
Date: Tue, 13-May-86 13:22:33 EDT
Article-I.D.: ur-tut.332
Posted: Tue May 13 13:22:33 1986
Date-Received: Thu, 15-May-86 06:20:44 EDT
References: <1363@unc.unc.UUCP> <467@cit-vax.Caltech.Edu> <384@astroatc.UUCP>
Reply-To: tuba@ur-tut.UUCP (Jon Krueger)
Distribution: net
Organization: Univ. of Rochester Computing Center
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Keywords:

In article <384@astroatc.UUCP> philm@astroatc.UUCP (Phil Mason) writes:
>[analogy between measuring mechanical power and compute power]
>I can think of two methods with which one may approach this:
>(1) Use machine independent standard tasks to grade performance between
>    different computers - The Benchmark Approach
>(2) Define a fundamental unit of information processing work 
>    - The Theoretical Approach 
>I am sure that some form of theoretical approach would bear fruit given
>enough fruit.  My initial guess is that it would have some relation to
>Turing machine theory as well as algorithm and information theory works
>that already exist.  Comments?

My guess as to why theoretical approaches haven't emerged as yet: we do
different things with our computers.  A mechanical task is usually
measurable as a single function.  A machine performs well for the function
for which it was designed, and very badly or not at all for any other
function.  By contrast, a piece of computer hardware, particularly a
processor for a general purpose computer, has many functions.  It's hard to
predict its performance on different functions based on

And of course, as your favorite hardware sales critter will tell you, his
hardware will perform better or worse on your application than his
benchmarks led you to believe.  The theoretical approach must overcome the
same problem.  My guess is that a "fundamental unit of information
processing work" will end up just as relative to an abstract machine as
Dhrystone is relative to its particular mix of integer, looping, and
subroutine calling.  Of course, measuring performance of your own
application beats either, and either beats MIPS.