A system and method of controlling the speed of a machine having a continuously variable transmission (CVT) operatively coupled to a power source. A plurality of selectable virtual gear ratios can be associated with the CVT. The machine may include an operator input device that may generate a operator input signal indicative of a desired adjustment in the ground speed. The operator input signal may be converted to a CVT speed command and to a power source speed command that are communicated to the CVT and the power source, respectively. The CVT adjusts the machine speed in accordance with the CVT speed command, while the power source adjusts its speed in accordance with the power source speed command, so that operation of the power source is substantially independent of operator of the CVT.