

Performance of CFD Applications on NASA Supercomputers
Abstract
We study the performance of three CFD applications of interest to NASA— Cart3D, OVERFLOW, and USM3D—on three Xeon-based SGI Altix ICE supercomputers and one Itanium-based SGI Altix 4700. The three ICE machines use different generations of Intel quad-core processors: Clovertown, Harpertown and the recently released Nehalem. We find that the Altix 4700 system does better than the Clovertown and Harpertown quad-core systems due to issues of cache size and memory bandwidth. However these challenges seem to have been addressed in the Nehalem. Also, when we compare performance in a way that attempts to compensate for large differences in cost, even the earlier quad-core systems can be more costeffective than the Altix 4700.