A computing device is disclosed comprising digital circuitry, and a gate speed regulator operable to generate a supply voltage applied to the digital circuitry. A frequency synthesizer generates a first reference frequency, and a propagation delay oscillator generates a first oscillation frequency in response to the supply voltage, wherein the first oscillation frequency is compared to the first reference frequency to generate a first error signal. A reference oscillator generates a second reference frequency in response to a reference voltage, and a startup oscillator generates a second oscillation frequency in response to the supply voltage, wherein the second oscillation frequency is compared to the second reference frequency to generate a second error signal. An adjustable circuit, responsive to the first and second error signals, adjusts the supply voltage applied to the digital circuitry.