Originally Posted by th3illusiveman
Good luck getting 120Fps at 1600p
That's a very good point.
You need to know what framerates you can maintain at a target resolution before saying you want a 120hz monitor for 120 FPS. If you get a screen that has such a large resolution that the card's fillrate isn't high enough to come close to 120 fps, and you aren't going SLI/CF, then you will wind up lowering details or lowering the resolution. And once you do that, what's the point?
1920x1080 is really the sweet spot, and if you have an emergency, you could reduce the game res to 1680x1050. But then you'll either have to use centered timings or things may look quite off with the screen stretched to full size, and a little off if the aspect ratio is preserved.
If you want a giant monitor for 120hz/120 fps, you need to make sure you have the horsepower for it.