On-line Optimization of Power Efficiency in 3D Multicore Processors

This paper considers the problem of maximizing power efficiency in multi-core processors by dynamic voltage frequency scaling. We formulate the problem in an on-line setting and apply to it a gradient-based stochastic approximation algorithm. We use a cycle-level, full-system simulation platform capable of realistic modeling of state-of-the-art microarchitectures executing industry-standard benchmarks (Splash 2). The optimization algorithm computes the gradients by the Infinitesimal Perturbation Analysis (IPA) sample-based sensitivity analysis technique. Despite the fact that the system’s characteristics vary widely with time and hence the optimum point varies as well, the simulation experiments exhibit a tracking of the optimal values. To our knowledge this is the first application of IPA to co-optimizing throughput performance and power in computer processors.