Adaptive Dynamic Frequency Scaling for Thermal-Aware 3D Multi-core Processors

3D integration technology can provide significant benefits of reduced interconnection delay and low power consumption in designing multi-core processors. However, the 3D integration technology magnifies the thermal challenges in multi-core processors due to high power density caused by stacking multiple layers vertically. For this reason, the 3D multi-core architecture cannot be practical without proper solutions to the thermal problems such as Dynamic Frequency Scaling(DFS). This paper investigates how the DFS handles the thermal problems in 3D multi-core processors from the perspective of the function-unit level. We also propose an adaptive DFS technique to mitigate the thermal problems in 3D multi-core processors by assigning different DFS levels to each core based on the corresponding cooling efficiency. Experimental results show that the proposed adaptive DFS technique reduces the peak temperature of 3D multi-core processors by up to 10.35°C compared to the conventional DFS technique, leading to the improved reliability.