Framebuffer and Video Surface Size
Two additional optional registry settings are available to limit the framebuffer size of the display driver and the total size of offscreen video surfaces.
The MaxFbSize registry entry will control the maximum size of the framebuffer only. Actual usage will depend on the mode being used.
The PageReqLimit registry entry will control the total size in pages (4 KB) of all video surfaces, buffers allocated for any use. Both of these registry configurations apply to both the static as well as dynamic video memory management explained in the previous section. The default below indicates that a maximum of 2 MB are used for the framebuffer and a maximum of 16 MB are permitted for all offscreen videosurface allocations.
In the case of Microsoft Windows Embedded Compact 7, because the OS does not allow for dynamically setting the framebuffer size, the MaxFbSize can be changed to match the mode setting being used in order to minimize on video memory waste. The following are different suggested values for MaxFbSize for different display modes. These values have not been validated. Note that 640x480 is calculated as 640x512 and 800x600 is calculated as 800x768 for stride alignment purposes.