Power Analysis of Mobile 3D Graphics

The world of 3D graphics, until recently restricted to high-end workstations and game consoles, is rapidly expanding into the domain of mobile platforms such as cellular phones and PDAs. Even as the mobile chip market is poised to exceed production of 500 million chips per year, incorporation of 3D graphics in handhelds poses several serious challenges to the hardware designer. Compared with other platforms, graphics on handhelds have to contend with limited energy supplies and lower computing horsepower. Nevertheless, images must still be rendered at high quality since handheld screens are typically held closer to the observer´s eye, making imperfections and approximations very noticeable. In this paper, we provide an in-depth quantitative analysis of the power consumption of mobile 3D graphics pipelines. We analyze the effects of various 3D graphics factors such as resolution, frame rate, level of detail, lighting and texture maps on power consumption. We demonstrate that significant imbalance exists across the workloads of different graphics pipeline stages. In addition, we illustrate how this imbalance may vary dynamically, depending on the characteristics of the graphics application. Based on this observation, we identify and compare the benefits of candidate dynamic voltage and frequency scaling (DVFS) schemes for mobile 3D graphics pipelines. In our experiments we observe that DVFS for mobile 3D graphics reduces energy by as much as 50%