Evaluation of Knight Landing High Bandwidth Memory for HPC Workloads

Abstract

The Intel Knight Landing (KNL) manycore chip includes 3D-stacked memory named MCDRAM, also known as High Bandwidth Memory (HBM) for parallel applications that needs to scale to high thread count. In this paper, we provide a quantitative study of the KNL for HPC proxy applications including Lulesh, HPCG, AMG, and Hotspot when using DDR4 and MCDRAM. The results indicate that HBM significantly improves the performance of memory intensive applications for as many as three times better than DDR4 in HPCG, and Lulesh and HPCG for as many as 40% and 200%. For the selected compute intensive applications, the performance advantage of MCDRAM over DDR4 varies from 2% to 28%. We also observed that the cross-points, where MCDRAM starts outperforming DDR4, are around 8 to 16 threads.