Based on dual supply and dual threshold voltages technique, a novel methodology optimizing global interconnect performance in presented in this paper. The new figure of merit (FOM) is first defined as a function of bandwidth, delay and power consumption of global interconnect. Then, the optimal dual voltages can be obtained to save interconnect power by maximizing FOM function within a given delay penalty. Simulations show that in 65 nm technology, for the allowed delay penalties of 5%, 10% and 20%, the proposed methodology saves 27.8%, 40.3% and 56.9% power compared with the case with single supply and single threshold voltages, respectively. It can also be found that more power savings are achieved with the technology improving. The proposed methodology can be used to design and optimize global interconnects.