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Improving the Performance Scalability of the Community Atmosphere Model

Journal Article · · International Journal of High Performance Computing Applications
 [1];  [2]
  1. Lawrence Livermore National Laboratory (LLNL)
  2. ORNL

The Community Atmosphere Model (CAM), which serves as the atmosphere component of the Community Climate System Model (CCSM), is the most computationally expensive CCSM component in typical configurations. On current and next-generation leadership class computing systems, the performance of CAM is tied to its parallel scalability. Improving performance scalability in CAM has been a challenge, due largely to algorithmic restrictions necessitated by the polar singularities in its latitude-longitude computational grid. Nevertheless, through a combination of exploiting additional parallelism, implementing improved communication protocols, and eliminating scalability bottlenecks, we have been able to more than double the maximum throughput rate of CAM on production platforms. We describe these improvements and present results on the Cray XT5 and IBM BG/P. The approaches taken are not specific to CAM and may inform similar scalability enhancement activities for other codes.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Laboratory (ORNL); Center for Computational Sciences
Sponsoring Organization:
DOE Office of Science; SC USDOE - Office of Science (SC)
DOE Contract Number:
AC05-00OR22725
OSTI ID:
1021964
Journal Information:
International Journal of High Performance Computing Applications, Journal Name: International Journal of High Performance Computing Applications Journal Issue: 1 Vol. 26; ISSN 1094-3420
Country of Publication:
United States
Language:
English

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