In this paper we propose the OPTNET, a novel optical network and associated coherence protocol for scalable multiprocessors. The network divides its channels into broadcast and point-to-point groups. The broadcast channels are used for memory block request, coherence, and synchronization transactions, while the point-to-point channels are utilized for memory block transfer operations. The three main distinguishing features of the OPTNET are: a) its broadcast channels behave well under high contention; b) its point-to-point channels do not require any access control mechanism; and c) it can achieve good communication performance at a low hardware cost. We use detailed execution-driven simulations of ten applications to evaluate a 16-node OPTNET-based multiprocessor. We compare our multiprocessor against highly-efficient systems based on the DMON and LambdaNet optical interconnects. Our results demonstrate that our system outperforms the DMON multiprocessors consistently for our applica...
Enrique V. Carrera, Ricardo Bianchini