equation in the above equation u201c p n u201d is the average number of entries in the front end queue for the n th interval and u201c b u201d is the branch misprediction rate the value u201c 1 b u201d is an indicator of the rate at which the fetch queue may be loaded and u201c 1 pn u201d is an indicator of average number of entries in the queue u201c t n u201d is the performance of front end at interval u201c n u201d u201c fn u201d is the frequency of the front end domain at interval n and u201c f n 1 u201d is the frequency of the front end domain at the following time interval once the energy and performance of the processor has been calculated according to the above equations in one embodiment the front end domain frequency and voltage can be adjusted for the next time interval n 1 at the end of each time interval n in one embodiment the selection of frequency and voltage is made according to the ratio the frequency and voltage selected for the interval n 1 are those that minimize the above ratio if two or more pairs are found that result in the same value r.