An integrated approach for managing the lifetime of flash-based SSDs

As the semiconductor process is scaled down, the endurance of NAND flash memory greatly deteriorates. To overcome such a poor endurance characteristic and to provide a reasonable storage lifetime, system-level endurance enhancement techniques are rapidly adopted in recent NAND flash-based storage devices like solid-state drives (SSDs). In this paper, we propose an integrated lifetime management approach for SSDs. The proposed lifetime management technique combines several lifetime-enhancement schemes, including lossless compression, deduplication, and performance throttling, in an integrated fashion so that the lifetime of SSDs can be maximally extended. By selectively disabling less effective lifetime-enhancement schemes, the proposed technique achieves both high performance and high energy efficiency while meeting the required lifetime. Our evaluation results show that the proposed technique, over the SSDs with no lifetime management schemes, improves write performance by up to 55% and reduces energy consumption by up to 43% while satisfying a 5-year lifetime warranty.