Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!jwt!john
From: john@jwt.UUCP (John Temples)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Difference between 386/33 & 486/25 not counting fp
Message-ID: <1991Apr13.154941.1204@jwt.UUCP>
Date: 13 Apr 91 15:49:41 GMT
References: <1164@gistdev.gist.com> <1991Apr12.073828.20663@agate.berkeley.edu> <1991Apr12.093457.4147@kessner.denver.co.us>
Organization: Private System -- Orlando, FL
Lines: 28

In article <1991Apr12.093457.4147@kessner.denver.co.us> david@kessner.denver.co.us (David Kessner) writes:
>Personal Workstation, Unix World, and UNIX Review has rated all 486/33's in the
>ballpark of 34-37,000 dhrystones.  All 486/25's in the 23-27,000 Range.  The
>386/33's get 15-18,000.  And the 386/25's get about 11-13,000.

>Anyway.  These figures would indicate that the 486 is twice as fast as the 386
>for the same clock speed.

No they don't.  They indicate that the 486 can run the Dhrystone twice
as fast as the 386.  You can't take a number like the Dhrystone and
bandy it about as the be-all end-all benchmark, like some folks do with
Norton SI.  You need to look at a system's performance over a wide
range of benchmarks before you start saying CPU X is twice as fast as
CPU Y.

I'm sure some of you remember a certain compiler maker who included
special Dhrystone optimizations in their C compiler.  Who's to say that
the 486 (either by design or by chance) doesn't run the instruction mix
that represents the Dhrystone more efficiently than it might run some
other instruction mix?

If you're going to buy a computer on which you'll be running the
Dhrystone as your main application, by all means, get the system which
has the best Dhrystone benchmark.  But if you plan on using your system
for anything else, you'll want to see how your other applications
perform on it.
-- 
John W. Temples -- john@jwt.UUCP (uunet!jwt!john)