Presentation with Multiple Heads

Applications can call the Present method either to present contents of back buffers for all heads at once or to present the back buffer for an individual head. For more information about Present, see the latest DirectX SDK documentation.

The runtime in turn makes independent sequential calls to the driver's DdFlip or DdBlt function. Because the display mode and refresh rate of each head might be different, these calls are always independent at the DDI level.