Your display is 120, that is your refresh rate. You will notice a smoothness difference up to 120. The benefits of running higher than your refresh rate are present in some specialized MP situations.
No, that's just my point, I was the same at 60hz and on crt's with sillyhigh refresh rates. Setting the refresh rate above 120hz, I don't notice the benefit, same with framerate, about 150fps seems to be my sweet spot, anything above that is a waste to me.
Even on a 60hz monitor, games felt far more responsive and fluid when their framerate was over 60fps. Your refresh rate might not be keeping up with the framerate and your brain and hands but it isn't synced so your eyes and brain are getting enough feedback for it all to be a lot smoother, fluid and responsive experience, if that makes sense. I'm talking specifically about multiplayer first person shooters here at 60hz and I've had a few drinks so I might be talking complete bollocks :lol:
All I know is that on my 60hz monitor, I could do a nice fast pan with the camera and pick out enemies, with the framerate capped it was less fluid, it turned into a blurry, jerky slideshow, everything was less sharp and more stilted and just not right. I had to slow the pace, actually, here's a good video to illustrate, I capped a random match back when I used to play mw2, that game was capped at 90fps, You can see, I had to adopt this sort of twitchy pigeon head flicking style so as not to pan and cause the jerky blurring. Apologies for the video quality and audio popping.
http://www.youtube.com/watch?v=ftQmP9m8epw
IMO it is not worth the extra stress on your system or the chance of cooking your card a la Starcraft 2 when it pumps out too many frames. Running more FPS than refresh will have more tearing on average than using a limiter set to your refresh. Limiter also wont have any lag concerns like Vsync does.
Yeah, until very recently I used dxtory to universally cap my framerate to 115fps, just under my refresh rate for that very reason but it caused jittering in a few engines so I just stopped using that feature.
To be honest, I don't notice any more tearing when the framerate goes over 120fps at 120hz, the refresh rate is fast enough for it not to be an issue for me, I mean, if I really concentrate, stare at something while panning really fast back and forth, I could pick it out.
Obviously I did notice it at 60hz but it's the lesser of two evils, as you say.
I agree, it's a waste pumping out over 150fps when I get no benefit from it but for the modern games that aren't capped that my rig can manage over 120fps on, it doesn't go much higher, I have good airflow and my systems nice and cool so I'm not going to worry about it.