In this model different partitions of the processors into disjoint processor groups can be exploited in a single parallel implementation. The parallel programming model is appropriate for grid based applications with computations and dependence pattern mainly aligned in horizontal or vertical directions.
For those applications we propose a systematic development process for message passing programs using orthogonal processor groups. The development process starts with an SPMD-like specification of tasks indicating horizontal and vertical sections. A mapping to orthogonal processor groups realizes a group SPMD execution model with different orthogonal processor groups and a final transformation generates the corresponding MPI-program.
In this paper, we describe the approach and present example applications which can benefit from an implementation with orthogonal processor groups. The runtimes are measured on a Cray T3E.