Algorithm-Switching-Based Last-Level Cache Structure with Hybrid Main Memory Architecture

In this research, we designed an algorithm-switching (AS)-based last-level cache (LLC) structure with DRAM-NAND Flash hybrid main memory architecture. In order to take full advantage of previous memory access patterns and achieve high performance in the upper level of memory hierarchy, an AS-based clustering engine that uses k-means, k-medoids and k-center clustering algorithms was applied to LLC. The proposed LLC consists of three major parts, namely a set-divisible cache, and victim and clustering buffers. The victim and clustering buffers efficiently managed the history of cache blocks evicted from the set-divisible cache through the AS-based engine mechanism. The experimental results that were evaluated using Redis application and YCSB benchmark show that compared with conventional LLC structure, the proposed AS-based LLC structure could reduce the total execution time by 19.50%, power consumption by 16.31%, and NAND-Flash memory write count by 8.6%.