H-ECC： Heterogeneity-aware ECC designs for MLC SSD
LI Hongyan1,2， GUI Chao2， XIAO Kun2
1.State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing， Wuhan University， Wuhan 430079， China； 2.School of Information Engineering， Hubei University of Economics ， Wuhan 430205， China
Abstract：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 heterogeneity-aware ECC schemes. Simulation results have shown that about 50% performance improvement and linear lifetime extension can be achieved by using the proposed heterogeneity-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.
2018, Vol. 52 
