A method is described which comprises propagating electronic signals
within circuitry comprising a transmitter to select a number of the
transmitter's lanes, set a speed for each of the lanes, and set at least
a driver supply voltage for each of the lanes. The number and speed
determine the transmitter's bandwidth. Power consumed by the transmitter
as a consequence of the lane number selection, lane speed setting and
driver supply voltage is less than a power that would have been consumed
by the transmitter had another available combination of lane number, lane
speed and supply voltage been effected for the transmitter.