Power Constrained Performance Optimization in Chip Multi-processors
Kai Ma · OhioLink ETD Center (Ohio Library and Information Network) · 2013
With the technology scaling in semiconductor industry, both the power density and the power consumption of processors keep increasing.Compared with traditional frequency increasing, integrating more cores on the processor chip offers the opportunity to explore inter-thread parallelism and better energy efficiency.Therefore, the processor design has officially entered a chip multi-processor era.However, the peak power consumption (i.e., power budget or power cap) of a processor is still constrained by the cooling capacity, power delivery limitation, or the limitations specified by the users for different management purposes.Accordingly, it is important to discuss the performance optimization with power constraints (i.e., power capping).Important as it is, power capping is also challenging.Fundamentally, the performance/power relationship of applications is unknown a priori due to runtime variations.Therefore, it is difficult to choose the optimal adjustment in a large possible adjustment space.In this document, we investigate different aspects of power capping such as considering more components (e.g, caches part) in addition to traditional core part, using new knobs (e.g, power gating), managing new emerging platforms (e.g, CPU-GPU hybrid systems), and using new cooling technology (e.g., thermal electric cooling) .First, we explore the opportunity to coordinate the cache part and the core part in CMP (i.e., chip multi-processor).Second, we investigate a scalable power capping algorithm that can leverage the inter-thread dependency of multi-threaded applications for optimized performance.Third, we integrate dynamic voltage and frequency Without the help of the following people, I would not have been able to complete my dissertation.My heartfelt thanks to: Dr. Xiaorui Wang, for his guidance.I could not have asked for a better mentor.Without his help, I would not have had the opportunity to change my specialization to Computer Architecture, nor would I have enjoyed the level of success I have achieved in this area of research.Dr. Yefu Wang, for his help with the feedback-control-based power control concept that ultimately developed into our Temperature-Constrained Power Control paper.