Transferring ecosystem simulation codes to supercomputers

Skiles, J. W.; Schulbach, C. H.

Many ecosystem simulation computer codes have been developed in the last twenty-five years. This development took place initially on main-frame computers, then mini-computers, and more recently, on micro-computers and workstations. Supercomputing platforms (both parallel and distributed systems) have been largely unused, however, because of the perceived difficulty in accessing and using the machines. Also, significant differences in the system architectures of sequential, scalar computers and parallel and/or vector supercomputers must be considered. We have transferred a grassland simulation model (developed on a VAX) to a Cray Y-MP/C90. We describe porting the model to the Cray and the changes we made to exploit the parallelism in the application and improve code execution. The Cray executed the model 30 times faster than the VAX and 10 times faster than a Unix workstation. We achieved an additional speedup of 30 percent by using the compiler's vectoring and 'in-line' capabilities. The code runs at only about 5 percent of the Cray's peak speed because it ineffectively uses the vector and parallel processing capabilities of the Cray. We expect that by restructuring the code, it could execute an additional six to ten times faster.

Document ID

19950017632

Acquisition Source

Legacy CDMS

Document Type

Technical Memorandum (TM)

Authors

Date Acquired

September 6, 2013

Publication Date

February 1, 1995

Subject Category

Report/Patent Number

Accession Number

95N24052

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Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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