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U.S. Department of Energy
Office of Scientific and Technical Information

Production runs on the CRAY-1

Technical Report ·
DOI:https://doi.org/10.2172/6043671· OSTI ID:6043671

Under a grant from the National Center for Atmospheric Research, users from several Argonne divisions executed programs on the CRAY-1. The objectives were twofold: to determine the feasibility of implementing large codes on the CRAY-1, and to decide what algorithm changes could be made to improve run time on a vector machine. In addition, it was hoped to evaluate the code produced by the new CRAY FORTRAN compiler. Large reactor codes were implemented with relative ease, requiring, for example, approximately two man-weeks to get a 56,000-card program running correctly. Certain difficulties were encountered, however, in transferring the large binary files required by a biomedical code. It is concluded that it is both feasible and desirable to implement large codes on the CRAY-1. Better instruction scheduling in the CRAY compiler reduced run times by 40 percent. With some rewriting in Assembler language to produce optimal code, the programs tested ran two to four times faster than on the IBM 370/195 or the 3033 at Argonne. Further improvement (up to twofold) was realized in several programs by substituting new algorithms to take advantage of the vector architecture of the CRAY. 8 tables.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
DOE Contract Number:
W-31109-ENG-38
OSTI ID:
6043671
Report Number(s):
ANL-79-68
Country of Publication:
United States
Language:
English