I'm actually kind of confused about how FPS is supposed to behave with Vertical Sync enabled -- what everybody says is that if you have V-Sync with a 60Hz screen, when the frame rate drops below 60 it immediately cuts to 45, and then 30, then 15.
But this is not what happens. When I drop below 60 FPS it goes down naturally and smoothly to any number - it could be 54 FPS, or 48, or 42, or anything else. So why do people say it's only supposed to be 60-45-30-15? How exactly is it supposed to work?