Backing Store
If the configuration contains many screens displaying distinct areas of a meta screen, the X Window servers should not allow backing store. This may be achieved by the -bs X server argument. Without backing store, the XmetaX proxy is able to further optimize drawing operations for speed (Screen tags).
Backing store support affects the playback of a recording, too. Fullscreen playback (Displaying) (Displaying) as well as copying (Copying) is carried out more efficiently, if backing store was or is disabled during recording.