Merry_Blind :
Ok, let's forget consoles then for a second, because I didn't think of the fact that they can't output at 120hz. If, for example, I had my PC hooked to the Swift monitor, set to 120Hz, and that the game I play has a fluctuating framerate going anywhere from 30fps to 90fps. Would I be able to use ULMB since the monitor is running at 120Hz? Despite the framerate being all over the place, and not ever at 120fps?
Thanks for your reply btw.
No problem. I enjoy discussing the topic.
Yes. You would. Because with ULMB on, the REFRESH RATE stays constant, despite your varying frame rate. The monitor (In regular, or in ULMB mode, with Gsync off) will only refresh the frame at a rate of every 8.33 ms (1 / 120Hz), regardless of your framerate. This has nothing to do with the 1ms response time. That's where your keyboard or mouse input lag comes in. This is also what causes horziontal tearing, which is what GSYNC aims to remove. If your FRAME rate is much higher, or much lower, than your monitor's REFRESH rate, you will observe lots of tearing. ULMB does not reduce tearing, just motion blur.
You don't have to hit 120 fps to refresh at 120 Hz, but you get the most benefit out of your monitor that way. So yes, you can play ULMB at any framerate, but you *will* notice stutter if you're playing in the 90s and then drop into the 30s. This is what traditionally VSYNC tries to remove, but introduces input lag as a side effect.
Gsync removes the stutter and the tearing with virtually no input lag. It makes it so your monitor will refresh at the same rate as your framerate. So if you set your monitor to 144 Hz, and turn GSYNC on, then suddenly your *Max* framerate becomes 144 Hz (can't update faster than the panel), and the refresh rate of the monitor (when the monitor displays new frames from the GPU) varies with the framerate of the game from any range of 35 FPS up to 144 FPS. If you drop below 30 FPS, the GSYNC module switches to traditional VSYNC.
GSYNC can be toggled on and off from the Nvidia Control Panel. This is how you can switch between GSYNC or ULMB depending on what type of game you want to play.