Energy-efficient hybrid coherence protocol for multicore processors

In multicore processors, a cache coherence protocol is used for maintaining the data coherence in private caches. Traditional snoop-based protocols used broadcasting messages for maintaining data coherence to result in many tag comparisons in private caches. However, the use of broadcasting messages consumes a considerable amount of energy as well as execution time because of tag comparisons. In this paper, an energy-efficient hybrid coherence protocol (EEHCP) is proposed to reduce energy consumption for maintaining the data coherence of private caches by reducing the amount of broadcasting messages and tag comparisons. According to the simulation results, the proposed EEHCP consumes 27, 18, and 46% less energy than the SFT (snoop filter table) protocol, the snoop-based protocol with the hybrid write strategy, and the traditional snoop-based protocol with MESI, and 18, 17, and 32% less execution time than these three protocols, respectively.