An apparatus is provided, where the apparatus includes a plurality of processing cores to execute a plurality of processes, a register to store an indicator that is to indicate a preference for either performance or energy efficiency, a first circuitry to determine an effective utilization of a first processing core, based on the indicator, and a second circuitry to select at least one of an operating voltage or an operating frequency of the first processing core, based at least in part on the effective utilization of the first processing core.