Optimization of a Parallel Ocean General Circulation Model

We describe our efforts to optimize a parallel ocean general circulation model. We have developed several general strategies to optimize the ocean general circulation model on the Cray T3D. These strategies include memory optimization, effective use of arithmetic pipelines, and usage of optimized libraries. Nearly linear scaling performance data is obtained for the optimized code, while the speed-up data for the optimized code also shows excellent improvement over the original code. More importantly, the single-node performance is greatly improved. The optimized code runs about 2.5 times faster than the original code, which corresponds to 3.63 Gflops on the 256-PE Cray T3D. Such a model improvement allows one to perform ocean modeling at increasingly higher spatial resolutions for climate studies.