A comparison of homogeneous hierarchical interconnection structures

Among the various proposal advanced to build massive parallel systems in which the number of computing units ranges in the thousands, hierarchical topologies share a number of interesting properties. The authors review these architectures and their applicability and reliability, with particular attention to connections complexity and the ability to exchange messages. The usual assumption of the multiple instruction multiple data (MIMD) computational paradigm is as follows: autonomous but cooperating tasks execute on different processing units in the system. The overall complexity of the systems is measured with the analysis of the diameter and of the increasing law that states the number of interconnections against the number of nodes in the system. The various architectures are compared in terms of links load and average internode distance