Another quick follow-up on the BenQ EX3501R (yawn).
“sss” noted that there’s an issue with their Nvidia GPU and regular 100 Hz operation, FreeSync most likely isn’t the issue here (greedy bastards). (S)He’s having missing frames leading to e.g. jerky mouse movements, which can also be detected by running the UFO test and taking a picture.

Well, so I did.
Radeon 380, 100 Hz, FreeSync enabled but not active in plain Windows mode. Test needed Chrome browser for a) performance (FF you laggy bitch) and b) V-Sync reasons, as FF cannot get its shit together, especially in full screen mode. […]