Evaluating the Intel Skylake Xeon Processor for HPC Workloads

Despite significant advances in the porting of scientific applications to novel architectures such as compute-optimized graphics processors, many-core processor/accelerators and, even special-purpose function units, the vast majority of scientific calculations are still performed on high-performance, commodity server processors. Even in the cases of applications which have been ported to new architectures, frequent serial sections still require strong server-class processor cores to compute as fast as possible. In this paper we report on a set of benchmark studies which evaluate Intel's latest Skylake Xeon server processor. Skylake represents a significant change in the Xeon product line with wider SIMD vector units, a redesigned cache architecture, and, an increased number of memory channels. The wider vector units provide 2x improvement for some compute-intensive applications and the combined memory changes can provide close to 2x the memory bandwidth. We evaluate these new hardware features on several HPC-relevant mini-applications and benchmarks, including, STREAM, LULESH, XSBench, HPCG and SW4Lite. Together, the new hardware functions provide up to 1.8x speedup on HPC benchmark codes when compared with the previous generation Haswell processor core, providing much greater utility to a broader range of HPC applications that rely on this class of compute node.