Optical Connection of Top-Level Supercomputers: Current Status and Future Expectations

This paper reviews the current use of optical connection in top-level supercomputers and describes future expectations. The inter-node interconnects of seven world's No.1 systems of the last decade are introduced focusing on the use of optical connection. The interconnect and system configuration of the current No.1 system Fugaku is also explained in detail. This paper also discusses the use of optical connection in future supercomputers. The system configuration and interconnect of Frontier, which is expected to become the world's No.1 supercomputer, is introduced. Towards the late 2020s, expectations for higher transmission speeds of 100 to 200 Gbps and the use of CPO are described. The impact of additional latency caused by FEC on parallel computing is also discussed.