In a way yes. Traditional monitors only refresh the image at 60 hz, which translates into 60 times in one second. This means that if a video card were to render the game at 120 fps, then the monitor won't be able to keep up. What happens is called tearing. the video card will take 2 images and mix them into 1 frame. This causes a line where the image was split to apear on the screen. Many games and video card drivers will allow you to use v-sync to negate this affect, but the end result is that your game will run at 60 fps. The only real solution to "truly" see the game at 120 fps is to buy a monitor that supports 120hz input. Usually that means getting a nvidia 3d capable monitor.