Performance Evaluation Of The Red Storm Dual-Core Upgrade

In 2007, the Cray Red Storm system at Sandia National Laboratories completed an upgrade of the processor and network hardware. Single-core 2.0 GHz AMD Opteron processors were replaced with dual-core 2.4 GHz AMD Opterons, while the network interface hardware was upgraded from a sustained rate of 1.1 GBps to 2.0 GBps (without changing the router link rates). These changes more than doubled the theoretical peak floating-point performance of the compute nodes and doubled the bandwidth performance of the network. This paper provides an analysis of the impact of this upgrade on the performance of several applications and micro-benchmarks. Performance results show that the additional core provides a performance boost of 20-50% for real applications on a fixed problem size per-socket basis on up to 2048 cores and that scalability is impacted relatively little by the upgrade. Copyright (C) 2009 John Wiley & Sons, Ltd.