An example process for controlling a processor may include: (i) obtaining parameters associated with operation of a processor, where each of the parameters has a different time scale; (ii) performing an iterative process to identify ones of the parameters that achieve a particular energy efficiency in the processor, where the energy efficiency of the processor corresponds to a quasi-concave function having a maximum that corresponds to the ones of the parameters; and (iii) controlling the processor using the ones of the parameters.