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PVM provides a portable programming model for implementing parallel applications on a wide variety of message-based MIMD systems. Many important scientific and industrial applications have been ported to PVM with the expectation to gain more independence from specific hardware platforms and vendors. First results from the Esprit project EUROPORT indicate, that it is possible to execute large PVM applications on various systems, ranging from moderately parallel symmetric multiprocessor systems to massively parallel systems with many hundred nodes.

Hardware independency, however, may tempt the programmer to use program features that might later be found inefficient on certain systems. Time-critical applications may need post-optimization to exploit specific MPP system features. As an example, PVM's clique-structured communication pattern is tailored for bus-connected workstation clusters (Ethernet, FDDI, ATM). As seen above, clique communication poses problems on massively parallel 2D systems, where the communication latency depends on the number of hops a message needs to reach the recipient. Here, nearest neighbor communication should be used instead.

Tue May 16 19:29:30 MET DST 1995