When used with a graphic chipset that supports multiple graphics pipelines, the driver supports multiple screens and Xinerama. Enable this support by creating additional Device sections for each additional graphics device on the PCIe bus. The driver locates the first device on the bus and associates it with the device section that matches (or one that does not specify a busID). This becomes the primary display. If the chipset supports multiple display pipes, and the config file specifies two Device sections and two Screen sections, the driver attempts to operate in a DIH mode. After all the graphics devices and device sections have been matched up, the driver attempts to allocate any remaining output ports and attach them to the primary graphics device.
For example, two pipes and two ports allow for dual independent displays.