Exploiting flash memory for reducing disk power consumption in portable media players

Abstract

Portable media players are increasingly using hard disk drives (HDD) to meet their storage requirements, but HDDs consume a significant amount of energy. Therefore video frames are prefetched into dynamic random access memory (DRAM) to allow the disk to go into low-power mode; but most mobile systems have limited DRAM, so little energy is actually saved in this way. We propose two new energy saving schemes: one improves the utilization of DRAM in storing prefetched frames, and the other extends this approach by making use of auxiliary flash memory. Simulations show that deploying a reasonable amount of auxiliary flash reduces disk energy consumption by up to 86% compared with conventional prefetching schemes.