Power-performance efficiency of asymmetric multiprocessors for multi-threaded scientific applications

Recently, under a fixed power budget, asymmetric multiprocessors (AMP) have been proposed to improve the performance of multi-threaded applications compared to symmetric multiprocessors. An AMP is a multiprocessor system in which its processors are not operating at the same frequency. Power consumption has become an important design constraint in servers and high-performance server clusters. This paper explores the power-performance efficiency of hyper-threaded (HT) AMP servers, and proposes a new scheduling algorithm that can be used to reduce the overall power consumption of a server while maintaining a high level of performance. Prototyping AMPs on a commercial 4-way SMP server, we show that on average 15.6% energy savings and 6.1% slowdown for the HT-disabled case, and 7.1% energy savings and 4.8% slowdown for the HT-enabled case can be achieved across NAS and SPEC OpenMP applications.