Concurrent Bidirectional Communication On The Intel iPSC/860 And iPSC/2

Abstract

Each node of the Intel iPSCI2 and iPSCl860 is capable of concurrent bidirectional communication, that is, each node can concurrently send and receive a message. However, link contention created by the long message communication protocol usually interferes with this source of concurrency so that half of the total capacity of the communication network is wasted. This intelference can be overcome by synchronizing communicating pairs of nodes. The cost of algorith,ms for the simple exchange, the one-to-all broadcast, the allto-all broadcast, and the complete exchange operations can be significantly reduced, compared to the cost of their usual implementations, by exploiting this approach. Performance measurements of algorithms for these communication problems support these observations.