Features of optical interconnects in distributed-shared memory organized MIMD architectures: the ultimate goal

The antipode of a sequential computer, using a single CPU to execute the tasks, is a massively parallel processor containing large numbers of computing nodes. Supplemental to the shared and distributed memory organizations are the distributed-shared systems, allowing nodes to explore a single globally shared address space. A different vision is introduced concerning the prospects of an optically coupled version of such a system. In each cluster, an electrical crossbar looks after the interconnections between the nodes, the various memory modules and external I/O channels. The clusters are optically coupled through a free space oriented data distributing system. Analogies found in the design of the Convex SPP1000 validate the closeness to reality of such an architecture. An idealized picture of the fundamental properties of an optically based, fully connected distributed (virtual) shared memory architecture is outlined