G-sync necessary?

[Bacon1]

I get it now.In the situation where the game/cpu generate higher fps than the refresh rate, the fps # shown on the monitor is not the actual displayed # of frames. No matter what the game rendered fps # is, with a lower hz, the only frames one will actually see is the hz number, here 60. Fps are disconnected from actual display, buffered and then fed out to the display at 60 per second.Why didn't someone say that.lol.
Thx,

Yep!

Now if you don't have any kind of syncing, you will get the latest frame drawn on the screen (partly) and get tearing:

Spoiler

So imagine that person is panning the camera to the left. The first image has the trees farther on the left and they get pushed over each partial frame

The same thing happens under hz as well unless you have gsync/freesync. So if people are bothered by tearing these technologies are great because it lets them run w/o vsync and thus have no extra input lag but a great image with no tearing.