A data generator includes an over drive data generator and a buffer. The over drive data generator generates an over drive data based on a previous display data and a current display data. The buffer provides the previous display data to the over drive data generator. The buffer stores the current display data and the over drive data. The buffer outputs the current display data and the over drive data. The data generator may increase the speed of driving the load connected to a display driver using the over drive voltage corresponding to the over drive data. If the speed of driving the load connected to the display driver is increased, the operational speed of the display device may be increased.