Linpack benchmark

From: Harontas (harontas_at_hotmail.com)
Date: 05/29/04 

Date: Sat, 29 May 2004 14:31:05 +0300

I came accross the Linpack benchmark and I gave it a try at my PC (2.6 GHz
Pentium, Windows XP, CVF6.6).
I used a timing function that involves DATE_AND_TIME.

It seems that the first Linpack test (rank 100 linear system) is out of date
(!?).
The execution takes miliseconds to end and the results are negative
which according to Linpack FAQ means that the timing function is not
accurate enough.
Obviously it was designed for slower systems.

The second Linpack test (1000) lasts about 4 seconds.
(Compilation command: f90 -Optimize:5 1000d.f77 second.f77)
------------------------------------------------
     norm. resid resid machep
  6.49150133E+00 7.20701276E-13 2.22044605E-16 1

    times are reported for matrices of order 1000
      factor solve total mflops
 times for array with leading dimension of1001
  3.750E+00 -3.750E-04 3.749E+00 1.783E+02 1.121
  end of tests -- this version dated 10/12/92
------------------------------------------------
It reports a speed of 178.3 MFLOPs which is close enough to the java version
of the Linpack version (167 MFLOPs).
I find it hard to believe the results mentioned in netlib
(http://performance.netlib.org/performance/html/PDSbrowse.html),
since they are one order of a magnidute greater.

The third test (hpl), I didn't dare to touch, since it required a lot of
work and I didn't know if it is applicable my computer.

So my questions are:
1) Is there something basic that I might have overlooked in the comparison
with netlib archives?
2) Obviously this MFLOPs number is OS and compiler dependent. Is there a
universel method/program
    of determing a MFLOPs number for a certain hardware setup, independent
of software?
3) Can the java version of Linpack be considered as one?
4) Wouldn't it be better if vendor's included a MFLOPs number among the
spefications of a computer, even
    if it refers to a certain software setup?

Thank you in advance.