An Adaptive Separation-Aware FTL for Improving the Efficiency of Garbage Collection in SSDs

Hot/cold data separation in flash-based solid state drives has been considered important to the overall performance due to the costly garbage collection overhead. This work proposes a method that accurately and naturally identifies and separates hot/cold data while only incurs minimal overhead. The proposed method only requires minimal on-device RAM space. Simulation results have shown that the proposed ASA-FTL reduce the GC overhead by up to 33% and improve the overall response time by 9% against the most advanced existing FTL in both real workloads and synthetic workloads.