Nvidia Control Panel V-SYNC vs. In-game V-SYNC
While NVCP V-SYNC has no input lag reduction over in-game V-SYNC, and when used with G-SYNC + FPS limit, it will never engage, some in-game V-SYNC solutions may introduce their own frame buffer or frame pacing behaviors, enable triple buffer V-SYNC automatically (not optimal for the native double buffer of G-SYNC), or simply not function at all, and, thus, NVCP V-SYNC is the safest bet.
There are rare occasions, however, where V-SYNC will only function with the in-game option enabled, so if tearing or other anomalous behavior is observed with NVCP V-SYNC (or visa-versa), each solution should be tried until said behavior is resolved.
