Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!tank!zaphod.uchicago.edu!barry
From: barry@zaphod.uchicago.edu (Barry Merriman)
Newsgroups: comp.sys.next
Subject: Number Crunching on the Cube?
Keywords: number crunch
Message-ID: <4696@tank.uchicago.edu>
Date: 27 Jul 89 23:31:40 GMT
Sender: news@tank.uchicago.edu
Reply-To: barry@zaphod.uchicago.edu (Barry Merriman)
Distribution: usa
Organization: Dept. of Mathematics, Univ. of Chicago
Lines: 53

_
_
How good is the Cube at pure number crunching? Does anyone
have some benchmarks comparing it to, say, some flavor of Sun?
Please post them if you do.

If you have a Cube handy, try this trivial benchmark:

  Write a program that multiplies 1.000001 (double precision) 
  against itself 10^6 times, 
  and time it with the unix "time" command. Try it with and without 
  the floating point chip. 

For comparison, here are the elapsed
cpu times for some of our local Suns, and the inferred MFLOPage:

[Notes: 68881 denotes the Motorola MC68881 floating point
coprocessor; all runs were compiled with the -O optimization option
on the f77 compiler, which makes about a factor of 4 improvement
when using the MC68881.]
------------------------------------------------------------------

  Machine (options)    cpu time/sec    MFLOPs   Comments
  ------------------   ------------    ------   --------
  Sun 3/50               101.4         0.01
  Sun 3/50 (68881)         4.3         0.23     20x speedup

  Sun 3/60                66.1         0.015     
  Sun 3/60 (68881)         3.7         0.27     18x speedup

  Sun 3 Server            47.8         0.02
  Sun 3 Server (68881)     3.5         0.29     14x speedup

and, just for fun, our local
throwback to
the centralized computing
era

  ELXSI 6400               2.1         0.48     cost > $200K


  NeXT Cube                ???         ????     ???????????

------------------------------------------------------------

Any info on Cube processing speeds (and the speed of the
optical drive---measured in units of user pain) is appreciated.

-thanks

Barry Merriman
University of Chicago,
Dept of math