A method of selecting device (14-16, 18-24, 28-30) threshold voltages for high speed and low overall power involves identifying (42) the critical paths by predetermined timing criteria. All transistors have an initial, typically high, threshold voltage (40). Transistors outside the critical paths keep the initial high threshold voltages to minimize static power drain. The transistors in the critical path are selected (43) according to a predetermined sorting function to have a low threshold voltage and thereby switch faster. Although the lower threshold voltage devices consume more static power in standby mode, the power drain is accepted as a trade-off in favor of increased speed through the critical path. The supply voltage is reduced to minimize dynamic power. The integrated circuit is thus optimized to run at a higher frequency with lower overall power consumption.