QPACE: Quantum Chromodynamics Parallel Computing on the Cell Broadband Engine

We give an overview of the QPACE project, which is pursuing the development of a massively parallel, scalable supercomputer for applications in lattice quantum chromodynamics (QCD). The machine will be a three-dimensional torus of identical processing nodes, based on the PowerXCell 8i processor. These nodes will be tightly coupled by an FPGA-based, application-optimized network processor attached to the PowerXCell 8i. We first present a performance analysis of lattice QCD codes on QPACE and corresponding hardware benchmarks. We then describe the architecture of QPACE in some detail. In particular, we discuss the challenges arising from the special multi-core nature of the PowerXCell 8i and from the use of an FPGA for the network processor.