A Performance Evaluation of an Alpha EV7 Processing Node

In this paper we detail the performance of a new Alpha-Server node containing 16 Alpha EV7 CPUs. The EV7 processor is based on the EV68 processor core that is used in terascale systems at Los Alamos National Laboratory and the Pittsburgh Supercomputing Center. The EV68 processor core is supplemented with six-way router circuitry that forms connections from the processor internals to four neighboring CPUs in a two-dimensional torus, to a I/O controller and to local memory. The performance evaluation presented in this paper considers memory hierarchy, intra-node MPI communication, and also the performance of a number of complete applications. The measurements are compared with those taken on existing AlphaServer machines. It is clear from our analysis that the superior application performance of the EV7 relative to a similarspeed EV68 is attributable to its excellent main memory bandwidth - over 4 GB/s.