Abstract: Apparatus and methods are provided for allowing two graphics controllers to cooperate on a single screen and for modifying the AGP protocol to provide symmetric capabilities for both AGP targets and AGP masters. According to one embodiment of the present invention, an Accelerated Graphics Port (AGP) master may initiate a data transaction. A graphics controller receives an AGP transaction request from a core logic device. The graphics controller buffers the AGP transaction request in a request queue. Then, the graphics controller initiates a data transaction in response to the AGP transaction request.

Abstract: A system and method is provided for enhancing the efficiency with which commands from and initiating device to a resource are processed by the resource. The system includes a command queue, a plurality of command reorder slots coupled to the command queue, and command selection logic coupled to the resource and the command reorder slots. Commands ready for processing are loaded into the command reorder slots, and the command selection logic applies an efficiency criterion to the loaded commands. A command meeting the efficiency criterion is transferred to the resource for processing. The system may also include response reordering logic, which is coupled to the command reorder logic. The response reorder logic returns to original command order data provided in response to reorder read commands.