Low-Overhead Core Swapping for Thermal Management

Technology scaling trends and the limitations of packaging and cooling have intensified the need for thermally efficient architectures and architecture-level temperature management techniques. To combat these trends, we evaluate the thermal efficiency of the microcore architecture, a deeply decoupled processor core with larger structures factored out as helper engines. We further investigate activity migration (core swapping) as a means of controlling the thermal profile of the chip in this study. Specifically, the microcore architecture presents an ideal platform for core swapping thanks to helper engines that maintain the state of each process in a shared fabric surrounding the cores. This results in significantly reduced migration overhead, enabling seamless swapping of cores. Our results show that our thermal mechanisms outperform traditional Dynamic Thermal Management (DTM) techniques by reducing the performance hit caused by slowing/swapping of cores. Our experimental results show that the microcore architecture has 86% fewer thermally critical cycles compared to a conventional monolithic core.