Improving Performance and Lifetime of Large-Page NAND Storages Using Erase-Free Subpage Programming
Myungsuk Kim, Jaehoon Lee, Sungjin Lee, Jisung Park, Jihong Kim · 2017
Recent NAND flash devices have large page sizes. Although large pages are useful in increasing the flash capacity, they can degrade both the performance and lifetime of flash storage systems when small writes are dominant. We propose a new NAND programming scheme, called erase-free sub-page programming (ESP), which allows the same page to be programmed multiple times for small writes. By avoiding internal fragmentation, the ESP scheme reduces the overhead of garbage collection for large-page NAND storages. Experimental results show that an ESP-aware FTL can improve the IOPS and lifetime by up to 74% and 177%, respectively.