RTTM: A New Hierarchical Interconnection Network for Massively Parallel Computing

Since reducing the diameter is likely to improve the performance of an interconnection network, the problem of designing interconnection network with low diameter is still a current research topic. Another important issue in the design of interconnection networks for massively parallel computers is scalability. A new hierarchical interconnection network topology, called Rectangular Twisted Torus Meshes (RTTM network), is proposed. At the lowest level of RTTM network, the Level-I sub-network, also called a Basic Module, consists of a mesh connection of 2(m)x2(m) nodes. Successively higher level networks are built by recursively interconnecting ax2a next lower level sub-networks in the form of a Rectangular Twisted Torus. An appealing property of the RTTM network is its smaller diameter and shorter average distance, which implies a reduction in communication delays. The RTTM network allows the exploitation of computational locality as well as easy expansion up to a million processors.