This is actually one of the bigger cause of GSYNC flicker than TN fade-to-white! (but is kind of related, inversion balances the fading effect)Īlso, another possible fix - it could predictively automatically do an early re-refresh, and keep re-refreshing more often until the GPU was very certain that the currently-rendering frame is finished during the next ~1/144sec (the time of a refresh scanout).
So you got asymmetric time between polarities leading to the flicker problem. Y.ou end up getting stationary checkerboard pattern effects that briefly flicker to opposite polarity and then back. Especially at framerates just below or above 30fps. This actually causes more of the flicker, than the TN nature of fading to white. You can see in the TestUFO test that inversion causes artifacts on most LCD displays. The inversion artifact looks like a fine checkerboard pixel pattern (see TestUFO Inversion) caused by alternating DC polarities every opposite refresh passes, opposing DC voltage polarities, in a checkerboard pattern. I noticed a large proportion of flicker is caused by the LCD inversion algorithm, rather than TN fade-to-white.
Main source of GSYNC flicker is actually caused by “LCD Inverion” They’re not making 1440p 120Hz IPS Gsync yet. I can increase graphics settings (often to Ultra), add more AA, get 40-60 up to 144 fps, AND no screen tearing. And the AC Unity fiasco only reinforced that. But I don’t buy too many brand new games I wait for sales. When I enable Vsync, I lower graphics settings enough to keep frame times consistently 16.7ms. If better LCD panels aren’t the solution, then perhaps Nvidia simply needs to cook up a better algorithm for handling frame-rate stalls.
“As a result, the brightness value that is set during the LCD’s scanline update slowly relaxes until the next refresh.” “All LCD pixel values relax after refreshing,” Nvidia told the site.
PC Perspective says all of the variable-refresh displays it’s tested exhibit the same problem to some degree, and Nvidia is chalking up the problem to the way LCD monitors work. (In that game, the problem rears its head when the user snaps a screenshot.) What happens is basically a “very slight brightness variation,” which the site neatly graphed over time. PC Perspective measured this effect by taking continuous brightness readings in EVE Online with an Asus ROG Swift monitor. What you are seeing are the pixels intermittently bleeding towards white and periodically being pulled back down to the appropriate brightness by a scan. G-Sync displays can’t simply stop refreshing the image when that happens, so a failsafe measure kicks in:Ĭompletely stopping the panel refresh would result in all TN pixels bleeding towards white, so G-Sync has a built-in failsafe to prevent this by forcing a redraw every ~33 msec. Turns out the issue has to do with the way G-Sync handles “stalls” in game animation-that is, cases where the frame rate briefly dips to zero, as on some loading screens or when content loads in the background. The guys at PC Perspective did a little sleuthing this week, and they’ve both confirmed the problem and identified its cause. But they’re not perfect: some users have been reporting slight flickering in some games. Displays equipped with Nvidia’s G-Sync variable-refresh tech are pretty great.