Caps.MasterAdapterOrdinal Property (Microsoft.DirectX.Direct3D)
Retrieves a value that indicates which device is the master for the current subordinate.
This number is taken from the adapter values passed into the Manager.Adapters member.
For multihead support, one head is denoted the master head, and all other heads on the same card are denoted subordinate heads. If more than one multihead adapter is present in a system, the master and its subordinates from one multihead adapter are referred to as a group.