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Title: Experiments and improvements of the ordinary differential equation solvers DEPAC on the CRAY computer

Technical Report ·
OSTI ID:5640536

We have looked at timing results when solving large systems of differential equations using DEPAC on the CRAY computer. By reprogramming some critical (previously nonvectorized) loops, using loop unrolling where appropriate, and using the CRAY $SCILIB routines, significant speedup factors have been achieved. For example, when overhead is dominant (i.e., the derivative evaluation cost per component is minimal), we have observed cost reductions by factors of 2 to 7 when compared to the unmodified codes. We have also incorporated three additional user options which enable faster execution in appropriate circumstances. The modified DEPAC will replace the earlier package as part of the SLATEC library for use on the CRAY. The computational results produced are identical to those obtained by the earlier codes.

Research Organization:
Sandia National Labs., Albuquerque, NM (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
5640536
Report Number(s):
SAND-85-0856; ON: DE85013260
Country of Publication:
United States
Language:
English