Thermal Investigation Into Power Multiplexing for Homogeneous Many-Core Processors

In this paper, a proactive thermal management technique called “power multiplexing” is explored for many-core processors. Power multiplexing involves redistribution of the locations of active cores at regular time intervals to obtain uniform thermal profile with low peak temperature. Three different migration policies namely random, cyclic, and global coolest replace have been employed for power multiplexing and their efficacy in reducing the peak temperature and thermal gradient on chip is investigated. For a given migration frequency, global coolest replace policy is found to be the most effective among the three policies considered as this policy provides 10 °C reduction in peak temperature and 20 °C reduction in maximum spatial temperature difference on a 256 core chip. Power configuration on the chip is characterized by a parameter called “proximity index” which emerges as an important parameter to represent the spatial power distribution on a chip. We also notice that the overall performance of the chip could be improved by 10% using global multiplexing.