Vsync and game speed

[netninja]

I'm interested in using the VSync option for my next game.

If I have VSync on and my game's framerate is set to 1000FPS then the game will run at 60FPS (as my screen is 60hz). However if someone had a screen with 120hz, would the game run at 120FPS and therefore twice the speed of the other computer?

Similarly if I set the game's framerate to 60FPS and my screen's refresh rate is 50hz, doesn't that mean that the game will only run at 50FPS and hence 10FPS slower than the intended speed?

The Vsync option seems a bit useless if it is that inconsistent across computers.

Oddly enough if I have both Machine Independent Speed and Vsync on with the Framerate set to 1000, my game runs at 200FPS, despite my monitor running at 60hz.

[Dynasoft]

That's exactly how vsync works, yes.