When VSync is turned on, the scrolling rooms do scroll noticeably smoother. But is there a simple way to capture the real number of the cycles the game is locked to in this case (via GetGameSpeed)? The problem is that the game still returns the standard 40 cycles, though I know the refresh rate is at 85 :)
The Debug (http://www.adventuregamestudio.co.uk/manual/Debug.htm) command should give you get the actual FPS (Debug(4,1)), provided the game is in debug mode. If it's not, there's Scorpiorus' Scripted FPS function (http://www.adventuregamestudio.co.uk/yabb/index.php?topic=5388.0), which I think still works.