A case for a more effective, power-Efficient turbo boosting

Abstract

Single-thread performance and throughput often pose different design constraints and require compromises. Mainstream CPUs today incorporate a non-trivial number of cores, even for mobile devices. For power and thermal considerations, by default, a single core does not operate at the maximum performance level. When operating conditions allow, however, commercial products often rely on turbo boosting, which temporarily increases the clock frequency to increase single-thread performance. However, increasing clock speed May result in a poor performance return for invested energy. In this article, we make a case for a more effective boosting strategy, which invests energy in activities with the best estimated return. In addition to running faster clocks, we can also use a look-ahead thread to overlap the penalties of cache misses and branch mispredicts. Overall, for similar power consumptions, the proposed adaptive turbo boosting strategy can achieve about twice the performance benefits while halving the energy overhead.