To solve the more and more serious power and energy problem in computer science field, most researchers working on system software focus on real-time operating system, but the work of this paper is aimed at the commodity, sharingtime operating system. Analyzing the relationship among performance, frequency and memory accessing density, as well as the relationship between frequency and energy, a
Performance-Energy Tradeoff Model
, named T-model, is presented in this paper. Using T-model, we can get the
Best Low-energy Frequency
, counting the cost of some performance loss, conveniently. Then TDFG (
T-model based Dynamic Frequency Governor
) is proposed. Experimental results validated the correctness and efficiency of T-model and TDFG.