1. A machine implemented method comprising: generating a data structure having an identifier of a graphics resource assigned to a physical memory location in video memory; and controlling access to the physical memory location in response to determining if a data within the physical memory location is in transition between video memory and system memory wherein a client application accesses memory in the system memory at least in part through a first virtual memory map and wherein the client application accesses memory in the video memory through a second virtual memory map at least when writing data from a processor, through a memory controller, to the video memory without writing the data to the system memory; authorizing access to the physical memory location if the data within the physical memory location is not in transition; selecting a bus from one of a system memory bus and a graphics controller bus based on an available performance of the system memory bus and an available performance of the graphics controller bus; extracting the graphics resource from a system memory using the selected bus, and transmitting the graphics resource to a video memory.