Computational aspects of a code to study rotating turbulent convection in spherical shells

The coupling of highly turbulent convection with rotation within a full sph erical shell geometry, such as in the solar convection zone, can be studied with the new anelastic spherical harmonic (ASH) code developed to exploit massively parallel architectures. Inter-processor transposes are used to en sure data locality in spectral transforms, a sophisticated load balancing a lgorithm is implemented and the Legendre transforms, which dominate the wor kload for large problems, are highly optimized by exploiting the features o f cache memory and instruction pipelines. As a result, the ASH code achieve s around 120 Mflop/s per node on the Gray T3E and scales nearly linearly fo r adequately large problem sizes. (C) 1999 Published by Elsevier Science B. V. All rights reserved.