High-performance computing (HPC) denotes the design, build or use of computing systems substantially larger than typical desktop or laptop computers, in order to solve problems that are unsolvable on these traditional machines. Today's largest high-performance computers, a.k.a. supercomputers, are all organized around several thousands of compute nodes, which are collectively leveraged to tackle heavy computational problems. This orchestrated operation is only possible if compute nodes are able to communicate among themselves with low latency and high bandwidth.
This chapter presents the evolution of HPC architectures of the years, with particular focus on the interconnection networks. The future role of emerging optical technologies in building these interconnects is also evoked