Multistage ring network: An interconnection network for large scale sharedmemory multiprocessors

Unidirectional ring-based networks are currently popular choices for high p erformance large scale shared memory multiprocessors. This class of network s is attractive for their simple hardware interfaces, high speed communicat ion, wider data path, and easy addition of extra nodes. However, a single r ing does not scale well due to the fixed bandwidth, and the hierarchical ri ng networks as a natural extension of a single ring show limited scalabilit y due to their limited bandwidth near the root. In this paper we present a new interconnection network called the Multistage Ring Network (MRN). The M RN has a 2-level hierarchy of rings, and its interconnection of global ring s forms a type of the multistage network. The architecture of the MRN is ef fective at diffusing the global traffic on the network to all global rings, and the bandwidth of the network increases proportionally with increases i n the system size. Our results show that in a peak throughput, the MRN perf orms seven times better than the hierarchical ring network for system size of 1024. (C) 2000 Elsevier Science B.V. All rights reserved.