Power Modeling for Heterogeneous Processors

As power becomes an ever more important design consideration, there is a need for accurate power models at all stages of the design process. While power models are available for CPUs and GPUs, only simple models are available for heterogeneous processors. We present a micro-benchmark-based modeling technique that can be used for chip multiprocessor (CMPs) and accelerated processing units (APUs). We use our approach to model power on an Intel Xeon CPU and an AMD Fusion heterogeneous processor. The resulting error rate for the Xeon's model is below 3% and is only 7% for the Fusion. We also present a method to reduce the number of benchmarks required to create these models. Instead of running micro-benchmarks for every combination of factors (e.g. different operations or memory access patterns), we cluster similar micro-benchmarks to avoid unnecessary simulations. We show that it is possible to eliminate as many as 93% of the compute micro-benchmarks, while still producing power models having less than 10% error rate.