No, it's not necessary. It's just recommended to avoid possible other engine settings from being enabled that assume vsync is active. Settings like using vsync as a timing source or enabling triple buffering which is useless with freesync/gsync. Generally, it's best if the game thinks it's running with vsync off, because really, it is running with vsync off.MrBrown wrote:As far as i understand on pc its required to turn off vsync inside game’s settings (engine) in order to take advantage of freesync/gsync.
60Hz vsync lag is actually quite big, even if the engine had zero lag. I'm not very familiar with the xbox graphics stack, but I think three buffers are a given on that platform because almost no game can sustain 60FPS. So it needs three frame buffers to be able to output frame rates between 30 and 60. With only two buffers the game would only be able to output 60FPS, 30FPS, 20FPS, and so on; only integer dividers of the refresh rate. Some games avoid this by using adaptive vsync (they disable vsync when they fall below 60FPS), but games that are vsync ON and not adaptive, almost certainly are using triple buffering (three frame buffers.) And with 60Hz vsync, three frame buffers are worth 50ms of input lag. Freesync can reduce that to 16ms. A 33ms difference in input lag is something that can felt very easily with a mouse, and still quite easily with a controller.Most lag on consoles is usually caused by the game engine itself, but it would certainly help if the lag could be further reduced indeed.
It's likely that there are games however that do a good job of reducing vsync-induced input lag by frame limiting their output. These games will see smaller input lag benefits, but there still will be a good benefit. Although it might be a bit harder to tell with a controller as compared to a mouse, unless you're playing a game like a "Mario-like" platformer where pressing a button to jump for example reveals input lag very easily. Or fighting games like the Street Fighter series. These games already try to reduce input lag as much as possible, but 120Hz freesync should in theory make them even better, since these games are more sensitive to input lag.