An evaluation of architectural platforms for parallel Navier-Stokes computations

We study the computational, communication, and scalability characteristics of a computational fluid dynamics application, which solves the time-accurate flow field of a jet using the compressible Navier-Stokes equations, on a variety of parallel architectural platforms. The platforms chosen for this study are a cluster of workstations (the LACE experimental testbed at NASA Lewis), a shared-memory multiprocessor (the GRAY Y-MP), and distributed-memory multiprocessors with different topologies (the IBM SP and the GRAY T3D). We investigate the impact of various networks connecting the cluster of workstations on the performance of the application and the overheads induced by popular message-passing libraries used for parallelization. The work also highlights the importance of matching the memory bandwidth to processor speed for good single processor performance. By studying the performance of an application on a variety of architectures, we are able to point out the strengths and weaknesses of each of the example computing platforms.