rate specifies the number of 0.1 millisecond intervals in the new rate. Initially, the rate is set at 40, meaning that the display is redrawn every 4 milliseconds. If the refresh rate is too fast for the hardware to draw an entire display, the hardware automatically switches to continuous refresh mode. In continuous refresh mode the hardware takes as much time as necessary to continuously redraw a display.
Changing the refresh rate does not affect the refresh of the color monitor which remains constant at 60 Hz.