Heterogeneity as key feature of high performance computing: the PQE1 prototype

Presents the results of a project aimed at assembling a hybrid massively parallel machine, the PQE1 prototype, which is devoted to the simulation of complex physical models. The analysis of some existing parallel architectures has revealed that general-purpose machines are largely over-dimensioned and often perform inefficiently in grand-challenge scientific applications. We have thus developed a heterogeneous parallel system which matches task heterogeneity with architecture heterogeneity: in fact, special-purpose massively parallel architectures, when coupled to general-purpose machines, are able to satisfy the requirements of complex scientific computing efficiently. We present the hardware structure and the software tools that have been developed for the PQE1 prototype. Starting from the concepts of machine granularity and task granularity, we show the necessity to exploit both high- and low-granularity parallelism in order to use the PQE1 system efficiently. Some examples showing application fields in which the PQE1 prototype has been successfully used are briefly described.