Mechanisms are provided for the sharing of graphics adapter resources among multiple partitions in a virtual machine environment. A first mechanism allows for the sharing of graphics adapter resources so that one partition, a video service partition, containing a graphics proxy process, can use this graphics proxy process to offer graphics adapter resources to another partition, a video client partition. The graphics proxy process controls access time by any given partition to the graphics adapter resources. In one aspect, it uses a time bank to control access time, and the time bank controls how long a virtual graphics adapter offered to the video client partition can access the graphics adapter resources. A second mechanism synchronizes virtual memory in the video client partition to virtual memory in the video service partition. A third mechanism allows for multiple video client partition overlays using a pixel-shader-based virtual overlay mechanism.