There are a number of different tests or benchmarks used to measure the
performance of a computer.

One common benchmark is the "LINPACK benchmark", which measures floating
point performance.  This benchmark solves a 100'th order dense system of
linear equations.  Here are some numbers based on the LINPACK benchmark
(in millions of floating point operations per second, Mflops) that show
the relative performance of Athena workstations:

     DEC 5000/25       ~2.5 Mflops
     Sun SparcClassic  ~3.3 Mflops
     Sun Sparc 5       ~7.2 Mflops
     Sun Sparc 4       ~9.5 Mflops
     SGI Indy	      ~12.8 MFlops

If you would like to see more detailed information, the numbers above
were generated with the "bench35" command in Matlab.

However...

		      BENCHMARKS CAN BE MISLEADING!

In order to asess any set of benchmarks, you have to know what is being
measured, and how it is being measured.  Consider the following results
obtained running an example from "Optimization and Tuning Guide for the XL
FORTRAN and XL C Compilers", IBM AIX version 3.2:

          Machine          Compile Command       Time         MFlops

       DEC 5000/25             f77             18.6 sec        8.57
       DEC 5000/25             f77 -O3         18.6 sec        8.57

       Sun SparcClassic	       f77	       61   sec        2.67
       Sun SparcClassic	       f77 -O3	       30   sec        5.33
       Sun Sparc5	       f77	       21   sec        7.62
       Sun Sparc5	       f77 -O3	        7   sec       22.86
       Sun Sparc4	       f77	       16   sec       10.00
       Sun Sparc4	       f77 -O3	        5   sec       32.00

       SGI Indy		       f77	        7.9 sec	      20.23
       SGI Indy		       f77 -O3 -mips2   3.6 sec	      44.20

As you can see there is large difference for this particular code between
the DEC, Sun, and SGI workstations and that sometimes optimization matters
greatly.

The source code used to get this times is located in the "fortran" locker:

       IBM RS6000      /mit/fortran/src/benchmarks/Flop.f
       DEC 5000        /mit/fortran/src/benchmarks/Flopunix.f


Last updated: 7/7/97