Proceedings of the Non-Volatile Memories Workshop (NVMW), San Diego, California, March 2011.
It is anticipated that some or all of the roles assumed by conventional rotating hard disk drives (HDDs) will migrate to solid-state storage devices (SSDs) and emerging persistent RAM storage devices (PSDs). SSDs are typically built with solid-state NAND flash memory and have already been deployed in data centers because of their performance and energy merits. Increasingly more researchers are exploring the potential of the SSD as HDD replacement or complement. While emerging persistent RAMs like PCM (Phase Change Memory) are touted as having more desirable physical characteristics than NAND flash memory, to date, there has been little work evaluating actual PSDs empirically. In this paper, we characterize the capabilities and peculiarities of the PSD as SSD alternative with a PSD prototype system built with 90nm PCM chips. We first identify which design parameters of the PSD may affect storage system performance and describe our measurement process. Next, we present the performance of the PSD interacting with the most recent Linux OS and provide some insights on the differences between the PSD and a SSD when serving I/O requests. Our results suggest that the different PSD and SSD characteristics should be taken into account to design an efficient storage system.