Packaging the Blue Gene/L supercomputer

As 1999 ended, IBM announced its intention to construct a one-petaflop supercomputer. The construction of this system was based on a cellular architecture—the use of relatively small but powerful building blocks used together in sufficient quantities to construct large systems. The first step on the road to a petaflop machine (one quadrillion floating-point operations in a second) is the Blue Gene®/L supercomputer. Blue Gene/L combines a low-power processor with a highly parallel architecture to achieve unparalleled computing performance per unit volume. Implementing the Blue Gene/L packaging involved trading off considerations of cost, power, cooling, signaling, electromagnetic radiation, mechanics, component selection, cabling, reliability, service strategy, risk, and schedule. This paper describes how 1,024 dual-processor compute application-specific integrated circuits (ASICs) are packaged in a scalable rack, and how racks are combined and augmented with host computers and remote storage. The Blue Gene/L interconnect, power, cooling, and control systems are described individually and as part of the synergistic whole.