Hello,
For a certain Fortran 90 calculation I get very different results depending
on whether I use Sun Workshop 4.2 or 5.0. The 4.2 results seem to be
correct, and they agree with results using a DEC computer.
The calculation is a Monte Carlo solution of the Boltzmann equation for
electric field driven transport in GaAs.
I suspect that the error may arise in the intrinsic random number generator
random_number. Perhaps it is implemented differently in Workshop 4.2 and
5.0? However, I don't see why a different implementation would cause the
large effects I see in the final results.
All of my source code is identical for these two calculations.
Any comments about known problems would be much appreciated because it can
be difficult to compare "identical" probabilistic calculations.
Meanwhile I will look into reviving some code that I used long ago to test
random number generators.
Harry
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Harold P. Hjalmarson
(Materials Simulation Sciences, Dept. 9225)
Sandia National Labs, MS-1111, PO Box 5800, Albuquerque, NM 87185-1111
[log in to unmask] (Internet) 505-844-8888 (office) 505-845-7442 (fax)
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