An apparatus and method to dynamically regulate system bandwidth in a graphics system includes receiving vertex data from an application by way of an application programming interface. The rate that the vertex data is received from the application is then determined. In the event the rate is greater than a selected threshold, the graphics system is configured to operate in immediate mode, wherein vertex data is rendered immediately upon reception. In the event the rate is less than the selected threshold, the graphics system is configured to operate in retained mode, wherein vertex data is stored prior to being rendered. The apparatus and method switches between each of the modes on-the-fly in a manner that is transparent to the application.