Frequency planning for multi-core processors under thermal constraints

The objectives of this paper are (1) to develop a frequency planning methodology that maximizes the total performance of multi-core processors and that limits their maximum temperature as specified by the design constraints; and (2) to establish the implications of technology scaling on the performance limits of multi-core processors. Given the intricate designs and workloads of multi or many-core processors, it is computationally exhaustive to develop models that accurately calculate the temperature and performance of a given processor under various operating conditions. To abstract the underlying design complexity, we propose the use of supervised machine learning techniques to develop versatile models that capture the thermal characterization of multi-core processors under various input conditions and workloads. We then use the developed models to create a framework where various design constraints and objectives are expressed and solved using combinatorial optimization techniques. Using established power modeling and thermal simulation tools, we show that it is possible to boost the performance of multi-core processors by up to 11.4% at no impact to the maximum temperature.