Performance analysis of the Alpha 21364-based HP GS1280 multiprocessor

Abstract

This paper evaluates performance characteristics of the HP GS1280 shared memory multiprocessor system. The GS1280 system contains up to 64 Alpha 21364 CPUs connected together via a torus-based interconnect. We describe architectural features of the GS1280 system. We compare and contrast the GS1280 to the previousgeneration Alpha systems: AlphaServer GS320 and ES45/SC45. We further quantitatively show the performance effects of these features using application results and profiling data based on the built-in performance counters. We find that the HP GS1280 often provides 2 to 3 times the performance of the AlphaServer GS320 at similar clock frequencies. We find the key reasons for such performance gains are advances in memory, inter-processor, and I/O subsystem designs.