Speedup and Power Scaling Models for Heterogeneous Many-Core Systems

Traditional speedup models, such as Amdahl’s law, Gustafson’s, and Sun and Ni’s, have helped the research community and industry better understand system performance capabilities and application parallelizability. As they mostly target homogeneous hardware platforms or limited forms of processor heterogeneity, these models do not cover newly emerging multi-core heterogeneous architectures. This paper reports on novel speedup and energy consumption models based on a more general representation of heterogeneity, referred to as the normal form heterogeneity, that supports a wide range of heterogeneous many-core architectures. The modelling method aims to predict system power efficiency and performance ranges, and facilitates research and development at the hardware and system software levels. The models were validated through extensive experimentation on the off-the-shelf big.LITTLE heterogeneous platform and a dual-GPU laptop, with an average error of 1 percent for speedup and of less than 6.5 percent for power dissipation. A quantitative efficiency analysis targeting the system load balancer on the Odroid XU3 platform was used to demonstrate the practical use of the method.