Performance, energy characterizations and architectural implications of an emerging mobile platform benchmark suite - MobileBench

In this paper, we explore key microarchitectural features of mobile computing platforms that are crucial to the performance of smart phone applications. We create and use a selection of representative smart phone applications, which we call MobileBench that aid in this analysis. We also evaluate the effectiveness of current memory subsystem on the mobile platforms. Furthermore, by instrumenting the Android framework, we perform energy characterization for MobileBench on an existing Samsung Galaxy S III smart phone. Based on our energy analysis, we find that application cores on modern smart phones consume significant amount of energy. This motivates our detailed performance analysis centered at the application cores. Based on our detailed performance studies, we reach several key findings. (i) Using a more sophisticated tournament branch predictor can improve the branch prediction accuracy but this does not translate to observable performance gain. (ii) Smart phone applications show distinct TLB capacity needs. Larger TLBs can improve performance by an avg. of 14%. (iii) The current L2 cache on most smart phone platform experiences poor utilization because of the fast-changing memory requirements of smart phone applications. Using a more effective cache management scheme improves the L2 cache utilization by as much as 29.3% and by an avg. of 12%. (iv) Smart phone applications are prefetching-friendly. Using a simple stride prefetcher can improve performance across MobileBench applications by an avg. of 14%. (v) Lastly, the memory bandwidth requirements of MobileBench applications are moderate and well under current smart phone memory bandwidth capacity of 8.3 GB/s. With these insights into the smart phone application characteristics, we hope to guide the design of future smart phone platforms for lower power consumptions through simpler architecture while achieving high performance.