On the importance of optimizing the configuration of stream prefetchers

Abstract

This paper provides a detailed analysis of how the parameters of hardware prefetchers affect the memory system performance. In particular, we found the configuration of the frequently used stream prefetcher to have a major impact on the runtime, making parameter optimizations imperative when comparing a stream prefetcher with other prefetching techniques. For example, we show that adjusting the prefetch distance to the optimal value can increase the average speedup over the SPECcpu2000 benchmark suite from 40% to 70%. Moreover, our investigation of the performance of runahead prefetching relative to stream prefetching shows that choosing a non-optimal stream prefetcher as a baseline can distort the results by as much as a factor of two.