This question still rolls on, what, 10 years+ later? It's simply:
- Gsync on in NVCP (also make sure it's on in your monitor's settings if it has the option)
- Vsync on in NVCP
- Vsync off in game
- Reflex on in game if it has it
- If a game doesn't have Reflex and you have the grunt to be pegging the framerate at your display's max Hz, set an FPS limit to a few fps under your display's refresh rate (RTSS is the best)
If you don't have vsync on in the NVCP, you will get 'tearing' in most games.
These are the facts established
years ago. Nothing has changed.
For a much more in depth guide and other tips see here:
https://blurbusters.com/gsync/gsync101-input-lag-tests-and-settings/14/