Energy efficiency is rapidly becoming a key constraint in the design of enterprise systems. By 2011, yearly data center energy consumption in the United States is projected to grow to over 100 billion kWh at cost of $7.4 billion. As much as 40% of this energy is consumed by DRAM and disks. Portable consumer devices, where battery life has long been a key concern, instead use faster and more energy-efficient Flash storage. Flash is non-volatile, has near-zero standby power draw, and each Flash read requires 30x less power than a DRAM read and three orders-of-magnitude less power than a disk access. Moreover, Flash provides far lower access latency and higher bandwidth than disks, approaching DRAM performance levels. Enterprise storage vendors have recently announced products that replace traditional disks with high-capacity Flash solid-state disks (SSDs). However, because they are accessed through interfaces optimized for legacy rotating disks, SSDs fail to fully-exploit the low latency and high bandwidth Flash can provide. Furthermore, replacing conventional disks with SSDs does not address the growing power consumption of severs' DRAM. In this project, we examine further opportunities, beyond SSDs, to save energy with Flash in enterprise systems by integrating Flash throughout the servers' storage and memory hierarchies. The long term goal of our research--to improve data center energy efficiency--has the potential to drastically reduce the carbon footprint of data centers and the need for additional power generation capacity.
