conservation strategies for MEMSbased storage devices

Power dissipation by storage systems in mobile comput-ers accounts for a large percentage of the power consumed by the entire system. Reducing the power used by the stor-age device is crucial for reducing overall power consump-tion. A new class of secondary storage devices based on microelectromechanical systems (MEMS) promises to con-sume an order of magnitude less power with 10–20 times shorter latency and 10 times greater storage densities. We describe three strategies to reduce power consumption: ag-gressive spin-down, sequential request merging, and sub-sector accesses. We show that aggressive spin-down can save up to 50 % of the total energy consumed by the device at the cost of increased response time. Merging of sequen-tial requests can save up to 18 % of the servicing energy and reduce response time by about 20%. Transferring less data for small requests such as those for metadata can save 40% of the servicing energy. Finally, we show that by applying all three power management strategies simultaneously the total power consumption of MEMS-based storage devices can be reduced by about 54 % with no impact on I/O perfor-mance.