For API environments, this value can provide a screen synchronisation helper by ensuring a certain amount of time has elapsed since the last buffer sent by the host during screen transitions.

 

Generally, this is a "ok but not that great" option to use.  Instead, the screen definitions facilities should be used to ensure proper synchronisation.  Either that, or a wait-for-update approach that then checks for screen readiness.

 

If proper techniques are being used, this value can be set to zero to speed-up transitions.