Energy–performance trade-off for processor sharing queues with setup delay

Despite the extensive literature on energy efficient control mechanisms for servers, only few studies address the processor sharing discipline. We study the energy–performance trade-off in an energy-aware MX/G/1-PS system using two popular cost metrics. Among a family of control policies that can possibly stay idle before going to sleep to save energy, the optimal policy is found to be a simple control that either leaves the server idle, or puts it to sleep immediately whenever it becomes idle.