BXI, Bull eXascale Interconnect, is the new interconnection network developed by Atos for High Performance Computing. In this paper, we first present an overview of the BXI network. The BXI network is designed and optimized for HPC workloads at very large scale. It is based on the Portals 4 protocol and permits a complete offload of communication primitives in hardware, thus enabling independent progress of computation and communication. We then describe the two BXI ASIC components, the network interface and the BXI switch, and the BXI software environment. We finally explain how the Bull exascale platform integrates BXI to build a large scale parallel system and we give some performance estimations. Keywords— Interconnect technologies; high performance computing; parallel and scalable system architecture
Said Derradji is Lead Hardware architect at Atos Bull technologies, Said Derradji has been working first on several custom ASIC design interconnecting processors and focusing on cache coherency. He also worked on board design and participated on TERA-100 system delivery in 2011 (ranking 9 in Top500.org). Since 2012, he is working in the hardware architecture team at Bull, which specified the open exascale supercomputer, code-named SEQUANA. His areas of expertise are on ASIC/FPGA design, HPC servers architecture and on high performance interconnect technology such as BXI (Bull Exascale Interconnect). He is BULL’s representative at PCI-SIG (PCI Special Interest Group) and IBTA (InfiniBand® Trade Association) consortiums.
