SAD Prefetching for MPEG4 Using Flux Caches

Abstract. In this paper, we consider flux caches prefetching and a media application. We analyze the MPEG4 encoder workload with realistic data set in a scenario representative for the embedded systems domain. Our study shows that different well known data prefetch mechanisms can gain little reduction in the cache miss ratios when applied on the complete MPEG4 application. Furthermore, we investigate the potential improvement when dedicated prefetching strategies are applied to the sum of absolute differences (SAD) kernels in MPEG4. We propose a flux cache mechanism that dynamically invokes cache designs with dedicated prefetching engines that can fully utilize the available memory bandwidth. We show that our proposal improves the cache miss ratios by a factor close to 3x