Performance Analysis of HPC Applications on the Aurora Supercomputer: Exploring the Impact of HBM-Enabled Intel Xeon Max CPUs

The Aurora supercomputer is an exascale-class system designed to tackle some of the most demanding computational workloads. Equipped with both High Bandwidth Memory (HBM) and DDR memory, it provides unique trade-offs in performance, latency, and capacity. This paper presents a comprehensive analysis of the memory systems on the Aurora supercomputer, with a focus on evaluating the trade-offs between HBM and DDR memory systems. We explore how different memory configurations, including memory modes (Flat and Cache) and clustering modes (Quad and SNC4), influence key system performance metrics such as memory bandwidth, latency, CPU-GPU PCIe bandwidth, and MPI communication bandwidth. Additionally, we examine the performance of three representative HPC applications — HACC, QMCPACK, and BFS — each illustrating the impact of memory configurations on performance. By using microbenchmarks and application-level analysis, we provide insights into how to select the optimal memory system and configuration to maximize performance based on the application characteristics. The findings presented in this paper offer guidance for users of the Aurora system and similar exascale systems.