High performance computing on the IBM Power8 platform

Abstract

This paper discusses the performance of IBM’s Power8 CPUs, on a number of skeleton, financial and CFD benchmarks and applications. Implicitly, the performance of the software toolchain is also tested - the bare-bones Little-Endian Ubuntu, the GNU 5.3 and the XL 14.1.3 compilers and OpenMP runtimes. First, we aim to establish some roofline numbers on bandwidth and compute throughput, then move on to benchmark explicit and implicit one-/three-factor Black-Scholes computations, and CFD applications based on the OP2 and OPS frameworks, such as the Airfoil and BookLeaf unstructured-mesh codes, and the CloverLeaf 2D/3D structured mesh simulations. These applications all exhibit different characteristics in terms of computations, communications, memory access patterns, etc. Finally we briefly discuss performance of an industrial CFD code, Rolls-Royce Hydra, and we show initial results from IBM’s CUDA Fortran compiler. Both absolute and relative performance metrics are computed and compared to NVIDIA GPUs and Intel Xeon CPUs.