1000 Frames per second (FPS)

[Roflcopter]

That is why vsync will help you, even if (especially since) it restricts FPS to a lower frame rate than what your system is capable of.

Double buffering (which is the usual method for V-Sync) introduces extra latency though which will really hurt your gameplay. Some graphics cards' drivers may allow you to force Triple Buffering though which gets the best of both worlds (frames synced to your display and no extra latency).

For this reason, either use Triple Buffering or don't use V-Sync at all. This is advice I really can't stress enough; practically all paid competitive players play without V-Sync. Above and beyond that, get a 120hz monitor (usually they're also 3D capable).