一种基于MLC SSD的异质感知的ECC设计方法

H-ECC:Heterogeneity-aware ECC designs for MLC SSD

已有研究发现,同一闪存芯片上的页面在性能、可靠性和持久性方面都存在很大差异.这种页面之间的异质性结构为设计和实现固态盘提供了新的探索空间.该文利用这种异质性结构来设计灵活的纠错码(ECC)从而提高固态盘的性能并延长其寿命.实验结果表明,采用异质感知的ECC方案可以获得大约50%的性能改进和线性的寿命增长.

Recent research has discovered that there exist wide discrepancies in aspects of performance, reliability, and endurance among pages on the same flash memory chips. The observed page heterogeneity has provided system architects new exploration space in designing and implementing SSDs. In this study, we propose to exploit this phenomenon to guide flexible Error Correction Code （ECC） designs. Specifically, we demonstrate how to improve SSD performance and extend SSD lifetime by employing heteroge- neity-aware ECC schemes. Simulation results have shown that about 50% performance improvement and linear lifetime extension can De achieved by using the proposed hetero-geneity-aware ECCs. Given the increasing differences among the flash memory pages as flash feature size continues to shrink, we anticipate more significance of the proposed schemes in future-generation SSD designs.