Characterizing and Understanding the Bandwidth Behavior of Workloads on Multi-core Processors

An important issue of current multi-core processors is the off-chip bandwidth sharing. Sharing is helpful to improve resource utilization and but more importantly and it may cause performance degradation due to contention. However and there is not enough research work on characterizing the workloads from bandwidth perspective. Moreover and the understanding of the impact of the bandwidth constraint on performance is still limited. In this paper and we propose the phase execution model and and evaluate the arithmetic to memory ratio (AMR) of each phase to characterize the bandwidth requirements of arbitrary programs. We apply the model to a set of SPEC benchmark programs and obtain two results. First and we propose a new taxonomy of workloads based on their bandwidth requirements. Second and we find that prefetching techniques are useful to improve system throughput of multi-core processors only when there is enough spare memory bandwidth.