Quality-aware mobile graphics workload characterization for energy-efficient DVFS design

Contemporary mobile platforms use mobile GPUs for graphics-intensive applications, and deploy proprietary Dynamic Voltage Frequency Scaling (DVFS) policies in an attempt to save energy without sacrificing quality. However, there have been no previous systematic studies to correlate the performance, power, and energy efficiency of mobile GPUs based on diverse graphics workloads to enable more efficient mobile platform DVFS policies for energy savings. For the first time we present a study of mobile GPU graphics workload characterization for DVFS design considering user experience and energy efficiency on a real smart-phone. We develop micro-benchmarks that stress specific stages of the graphics pipeline separately, and study the relationship between varying graphics workloads and resulting energy and performance of different mobile graphics pipeline stages. We use these results to outline opportunities for more efficient, integrated DVFS policies across the mobile GPU, memory and CPU hardware components for saving energy without sacrificing user experience. Our experimental results on the Nexus 4 smartphone show that it is important to characterize GPU hardware and graphics workloads accurately in order to achieve increased energy efficiency without degradation in graphics performance for better user experience. We believe that our observations and results will enable more energy-efficient DVFS algorithms for mobile graphics rendering in the face of rapidly changing mobile GPU architectures.