It seems as if you enabled V-sync (vertical sync.) in your nVidia graphics settings.
Vertical Sync. will lock your potential max framerate to your monitors Hz (I'm guessing 60) to avoid image tearing.
If you somehow forced V-sync on in your nVidia control panel, it will overrule most ingame settings.
Put the setting on "Off" or "Application Controlled" in "Manage 3D settings"