A method and system for optimizing a core voltage level of a portable computing device (“PCD”) and enhancing frequency performance of individual subcomponents are disclosed. A plurality of voltage values for a plurality of subsystems is determined. At least one subsystem is a multiplexed subsystem. Next, a reduced set of voltage values is calculated based on the plurality of voltage values and an optimized voltage level is determined for a shared power domain. The shared power domain is subsequently set to the optimized voltage level. If the optimized voltage level is determined to exceed a required voltage level for the at least one multiplexed subsystem when it is running the plurality of processing engines, a subset of the plurality of processing engines may be identified to process a workload of the multiplexed system at a more efficient level of power consumption than the full plurality of processing engines.