Dual-Page Mode: Exploring Parallelism in MLC Flash SSDs

MLC flash memory SSDs have gained much popularity in storage subsystems from mobile devices to data centers because of their high performance and low power consumption. The naturally rich internal parallelism of SSDs is one of the most important factors that contribute to the high performance. Many studies make use of the parallelism from various perspectives such as scheduler, SSD organization and data layout etc. To promote the performance. However, internal parallelism of SSDs has been limited to plane level so far. This paper extends the parallelism beyond plain level, exploring the parallelism among pages within a block. We propose dual-page mode that can access two pages simultaneously. Experimental results demonstrate that SSDs with dual-page mode can reduce the average response time by up to 38% compared with contemporary SSDs.