Oesterreichisches Forschungsinstitut fuer Artificial Intelligence (OeFAI) Schottengasse 3, A-1010 Wien Tel.+43-1-53532810,5336112 ------------------------------------------------------------------------- VORTRAG ******* Prof.Dr.Susanne HAMBRUSCH Purdue University West Lafayette, Indiana USA High Performance Computing: Can We Achieve Scalability and Usability? ----------------------------------------- High performance computing must meet seemingly contradictory goals: software development should be carried out in an architecture- and technology-independent environment, but both algorithms and system software should take full advantage of the hardware features of potentially diverse MPP (Massively Parallel Processors) systems. Distributed memory, message-passing MPPs, which include the Intel Paragon, IBM SP-2, and Cray T3D machines, have emerged as major high performance architectures. In this talk we discuss the impact of different MPP features on the performance of scalable algorithms. We show how parameters like the number of processors, the message size, cost of setting up a message, the bandwidth of the processors and the network, the latency, and the bisection width influence scalability. We describe a parallel model, the C^3-model, which gives an accurate prediction of algorithm per- formance and supports a realistic scalability metric. We argue that scalability is achieved by the use of poly-algorithms which employ a parallel model to make algorithm selection and that usability is enhanced through libraries incorporating poly-algorithms. We validate our approach for regular and irregular communication operations and discuss performance results for the Intel Paragon. Zeit: Donnerstag, 1.August 1996, 18:30 Uhr pktl. Ort: OeFAI, Schottengasse 3, 1010 Wien 1.