Buffer flush and address mapping scheme for flash memory solid-state disk

The flash memory solid-state disk (SSD) is emerging as a killer application for NAND flash memory due to its high performance and low power consumption. To attain high write performance, recent SSDs use an internal SDRAM write buffer and parallel architecture that uses interleaving techniques. In such architecture, coarse-grained address mapping called superblock mapping is inevitably used to exploit the parallel architecture. However, superblock mapping shows poor performance for random write requests. In this paper, we propose a novel victim block selection policy for the write buffer considering the parallel architecture of SSD. We also propose a multi-level address mapping scheme that supports small-sized write requests while utilizing the parallel architecture. Experimental results show that the proposed scheme improves the I/O performance of SSD by up to 64% compared to the existing technique.