A method, apparatus, and system are described in which operating characteristics of voltage regulator (VR) may be controlled. Example operating characteristics that are controlled may be 1) power conversion efficiency based on load demand on the VR, 2) response rate to a transient deviation from a regulated output parameter, such as voltage or current, of the VR based on either 1) measured load or 2) receipt of an indication from a first load communicating that anticipated load conditions may cause the transient deviation from a set point of the regulated output parameter due to a significant change in load demand, or other similar operating characteristic. The VR may select an operating input voltage from two or more input voltages to control the operating characteristics of the VR by receiving a selection signal. Other embodiments are described.