PERFORMANCE OF THE CRAY T3D AND EMERGING ARCHITECTURES ON CANOPY QCD APPLICATIONS

The Cray T3D, an MIMD system with NUMA shared memory capabilities and in principle very low communications latency, can support the Canopy f ramework for grid-oriented applications. CANOPY has been ported to the T3D, with the intent of making it available to 8 spectrum of users. T he performance of the T3D running Canopy has been benchmarked on five QCD applications extensively run on ACPMAPS at Fermilab, requiring a v ariety of data access patterns. The net performance and scaling behavi or reveals an efficiency relative to peak Gflops almost identical to t hat achieved on ACPMAPS. Detailed studies of the major factors impacti ng performance are presented. Generalizations applying this analysis t o the newly emerging crop of commercial systems reveal where their lim itations will lie. On these applications, efficiencies of above 25% ar e not to be expected; eliminating overheads due to Canopy will improve matters, but by less than a factor of two.