I/O Performance in Hybrid MIMD+SIMD Machines

Abstract. The impact of I/O in the parallel machine is becoming ever more important as the computational power of the processor and the throughput of the communication network are increasing. In this paper we show some scenarios of I/O in parallel machines, in particular we focus on a hybrid MIMD+SIMD architecture which is under the study of an initiative which involves the Italian National Agency for New Technology, Energy and the Environment (ENEA). By means of queueing network models we show also how to improve the performance of a SIMD application that alternates I/O and computations in a cyclic fashion