Path Priority Order
This section applies only to Windows 7 and later, and Windows Server 2008 R2 and later versions of Windows operating system.
The SetDisplayConfig CCD function determines that the active paths within the path array that is specified by the pathArray parameter are ordered such that SetDisplayConfig gives higher priority to lower number array path elements. The following items impact the ordering:
If SetDisplayConfig does not find an existing display configuration, SetDisplayConfig uses the path priority during the best mode logic in the search order. Therefore, SetDisplayConfig is more likely to satisfy a higher priority path at native resolution than a lower priority path.
In cloned paths, the highest priority path is the path on which flips are scheduled. Therefore, lower priority paths can be subject to minor tearing.
The DirectX graphics kernel subsystem uses the path priority (along with the GDI primary view) to derive the path-importance value that the subsystem passes to the ImportanceOrdinal member of the D3DKMDT_VIDPN_PRESENT_PATH structure in a call to the display miniport driver. The path-importance value impacts driver decisions, such as, to which path the driver should give priority in resource allocations. For example, the lower-ordinal path might have better access to overlays or to a higher quality controller.
The QueryDisplayConfig CCD function always returns the paths in priority order. If the QDC_ALL_PATHS flag is set in the Flags parameter of QueryDisplayConfig, QueryDisplayConfig returns all of the inactive path combinations following all the active path combinations in the paths array that the pPathInfoArray parameter specifies.