Analysis of the effectiveness of core swapping in modern multicore processors

One of the interesting thermal management techniques for multi-core processors is core swapping. In this paper, using the published power data and floorplans for two modern high-performance processors, we employ the well-known HotSpot tool to perform the thermal simulation of the core swapping mechanism. Our transient simulations show that by using core swapping technique, it was possible to either minimize the hot spot temperature in the Ivy Bridge chip by 5°C or increase the operating frequency by 17% and maintain the same temperature as in the case without core swapping. We also derive an analytical model of the activity migration mechanism between two cores which may serve as a tool to calculate the swapping frequency given the desired maximal temperature drop. The model also allows for the correlation of the cooling effectiveness with the performance penalty induced by the swapping.