Well im just talk about it, i know a small answer will do the same but im bored...
Delta Time is a very small unit, how small you can change in the Engine im unsing.
(delta time is now on 0.01 in my editor(I can change it up ore down, its a performance stuff))
1 frame per second = 25 Frames (This is the norm)
1 frame per second = 100 delta Timesteps (on 0.01 timestep)
So the Character understand 3 Times faster how to move and what button in your Keyboard/Mouse was pressed.
If you have 80 FPS in this game you have the same Gameplay like you running the original GunZ with (75/25 = 3), 80*3 FPS = 240 FPS.
This is just for the Input, how fast your game is rendering is up to your GPU and CPU, ore APU if you use one.
Maybe i change the Timestep down to 0.005 that means if your game running on 60 FPS so, 1 Frame per seconds = 200 delta Timesteps - 25 = 175/25 = 7*60 = 420 FPS in the original GunZ
But i think you dont need 420 FPS input speed.
PS: this is why tbf isnt working very well on a to high FPS Count because the game is to accurat