MT_ wrote: ↑16 Jan 2021, 17:16
Even in best case, it still adds input lag. It looses its 'raw' response.
G-SYNC feels like a totally new sync technology when you don't need to cap -- for example, playing a game that fluctuates 100-300fps feels nice on a 360Hz G-SYNC panel. Night and day compared to yesteryear's 144Hz and 165Hz G-SYNC panels.
You don't have the latency-inconsistency behaviours of framerate-below-max and framerate-above-max, preserving your latency muscle memory when your framerate range is within VRR range; so it essentially preserves raw response because gametime:photontime is much more stable consistent with G-SYNC than VSYNC OFF, because you don't have the latency-jittering effect of
(A) No VSYNC OFF microstutters;
(B) Nor needing a framerate cap for G-SYNC;
(C) Nor worrying about the latency-change effect of framerate-below-max versus framerate-above-max.
VSYNC OFF has more latency jitter, but its latency averages stays consistent through the crossing threshold (fps below Hz and fps above Hz), which keeps it feeling raw. But as long as you've got a ginormous VRR range that you can drive a truck through, G-SYNC can feel "raw" especially if your priority is very consistent gametime:photontime behavior without the jittering latency gradients of VSYNC OFF (even if absolute lag is lower).
However, the mousefeel will vary from game to game. In some cases, mousefeel may for example feel better with VSYNC OFF for CS:GO but feel better with G-SYNC for PUBG. But your mileage will vary.
The ability to uncap your game unlimited, without your framerate ever exceeding max Hz, means G-SYNC can stay rawfeeling for some games. Many competitive games never exceed max Hz, if you're using brute Hz (e.g. 360Hz panels) to keep G-SYNC beautifully fast. (120fps cap at 360Hz G-SYNC can be lower lag than 240fps cap on a 120Hz panel VSYNC OFF, thanks to the scanout lag mathematics).
The latency mathematics for G-SYNC at "
framerates permanently below Hz without needing to cap" (thanks to the virtue of a 360Hz monitor and games running permanently below 360fps without needing capping) makes G-SYNC magically better and lower lagfeel / more rawfeeling. You can still cap G-SYNC, for lag consistency purposes, like you already cap VSYNC OFF.
When (Hz is super high) AND (game framerate never exceeds Hz), the playing field on VSYNC OFF-versus-G-SYNC is much more level, and occasionally tilts G-SYNC in certain games (though not commonly CS:GO though). For example, the latency gradient of a VSYNC OFF frameslice is [0..frametime] between the two tearlines, but since the tearlines are jittering in location, the latency gradient is jittering all over the place, interfering with your muscle in certain ways -- especially the sawtooth lag of a framerate cap and slowly-scrolling tearlines (which creates a slewing-latency effect). Whereas, G-SYNC has a perfectly consistent latency gradient [0..1/360sec] from top-to-bottom edge, at ALL frame rates, at ALL random unexpected frametimes, at ALL stable or erratic frame rates. This can improve muscle despite having sometimes more lag for screen middle (1/720sec) or bottom (1/360sec), but there is now more perfect gametime:photontime consistency for all pixels on a screen surface.
During VSYNC OFF, gametime:photontime variances can vary by as much as a full refresh cycle, while during G-SYNC, gametime:photontime variances can vary by almost 0ms (Even if average lag is, say, 1/720sec higher for screen center on a 360Hz monitor -- the halftime of scanout lag). In other words, certain games means G-SYNC versus VSYNC OFF playing field is levelled out to a choice between a fixed +1/720sec display lag modifier for all frames (G-SYNC) versus a varying display lag [0ms...1/360sec] in the series of frames for the same said pixel.
The problem is this somewhat falls apart with games that wants to perpetually run at frame rates far beyond refresh rates; since now VSYNC OFF start to become clearly superior for games that stays above Hz, or frequently crosses the crossing point (fps gyrating below/above Hz).
Now, if framerates stay below Hz without needing to cap, then the playing field is totally rewritten brutally. Because of the randomization of tearline locations in adjacent frame, which causes the lag-jittering effect, and if you cap at an exact multiple of Hz (e.g. 240fps cap at 120Hz), you may create a slowly-scrolling tearline -- which can cause a latency sawtooth effect (you have the highest lag just above a tearline, and lowest lag just below a tearline .... and if the tearline is moving, then your vertical latency graident is "scrolling"!)
But the magic is, when you have a super-high refresh rate, you start to gain the zero-varying display lag for specific pixels.
YMMV, but many in esports play CS:GO or Valorant whose framerates exceed a 240Hz monitor, so G-SYNC advantages are lost lost on those situations. I recommend VSYNC OFF when your framerates almost always exceed refresh rate. Right Tool for Right Game.
But yes, stabilizing GPU frametime lag jitter by capping it is still useful, especially if you hate varying-frametime lag. Other latency causes (e.g. rendering lag / frametime lag) is a separate of display lag, and still exists. Consistent framerates means consistent GPU rendering lag (another part of the lag chain).