Optical Interconnect for Next-Generation Supercomputers based on Wavelength Division Multiplexed Clockwork Routing

Optical networks based on a combination of ´clockwork´ routing and wavelength division multiplexing (WDM) have significant advantages for applications such as the internal interconnection networks of very large supercomputing systems in which latency and scalability are critical. The absence of optical buffers and elimination of centralized contention arbitration are beneficial in terms of latency, whilst the use of wavelength division multiplexing provides large scalability. This approach allows scaling in size to interconnection networks as large as 2048 optical nodes in a single-stage architecture. This paper describes the first detailed analysis of traffic in such a large-scale network, and presents throughput and latency statistics obtained by simulation.