Brief Announcement: Power Management of Devices- When Should I Switch Off?

Increasing power costs has renewed interest in software based power optimizations. One of the key question that any soft-ware based mechanism needs to decide is: How long should I wait before changing the power state of a device? In this pa-per, we study the solution space of this problem based on the workload history and device characteristics. We model the workload as a distribution of idle times (collected online) and the device characteristics using break-even time(∆). Our analysis shows that one should not do any power savings if the mean of the idle time distribution is lower than ∆. We also show that being greedy (i.e. wait time = 0) gives the highest power savings for most of the well known distribu-tions. Our model is also able to capture special cases such as bimodal distributions