The operating rate of an electronic system is maximized without exceeding a thermal constraint, such as a maximum junction temperature of an integrated circuit (IC) or other portion of the electronic system. An operating parameter of the system that controls the thermal output of the system is calculated for an upcoming time period based upon the previously measured thermal performance relationship to the operating parameter level. If the predicted thermal performance will exceed a maximum allowable level of the thermal constraint, then the operating parameter is reduced by an amount calculated to keep the thermal constraint at a level just below the maximum allowable level, thus resulting in an optimal control approach to maximizing the system performance while not exceeding the thermal constraint.