Optics for Enabling Future HPC Systems

Increasing demand for computing power in scientific and engineering applications has spurred deployment of high-performance computing clusters. According to the TOP500 list, an industry respected report of the most powerful computer systems, the high-performance computing market entered the Teraflop era in 2005 (the entry point on the list became greater than 1 Teraflop) and anticipates entering the Petaflop era in 2015. Future HPC systems that are capable of running large-scale parallel applications will span thousands to tens-of-thousands of nodes; all connected together via high-speed connectivity solutions to form a Peta to multi-Petaflop clusters. There are several architectural approaches to interconnect nodes together to construct an HPC system, such as the use of a fat-tree (CBB) or a 3-D torus. The overall number of communication links grows with the size of the system. The physical medium for those Links have become a growing concern for large-scale platforms, as they tend to impact the system architecture, the system reliability and its cost. In the paper we review the requirements for HPC systems cabling, and in particular optical cables. Optical cables capabilities will become the main limitation for building systems at any scale according to the CPU, memory and interconnect roadmaps in the next few years.