So actually, display sync clock is never aligned with GPU. Even if they have the same clock speed, they could be out of sync by a microscopic amount and so even if the GPU outputs a solid framerate, you will get a random delay that you can't control or do anything about, since there is no communication between the display and the GPU. It's all luck based. With G-Sync, there will be some added communication / handshake delay, usually only 1ms on OLEDs, but the display will follow the GPU's pace, not relying on its own internal clock. So it's a trade between inconsistent luck based delay, vs. a stable processing delay. The only time G-Sync is worth disabling at all is in games where there are bugs related to it (rare), or if you're running the game at a framerate so high that even the full frame of delay (luck based), would be a smaller cost than 1ms delay of G-Sync. The equation is that on average, the delay you will get will be 1/2 your refresh rate latency. So for 60fps : 16.66ms / 2 = average latency of 8ms. (it's a terrible way to think of it but alright) So like, the only time where G-Sync off will be more worthwhile more than half of the time, is when that number goes under 1ms. Even at 240hz that's 4ms / 2 = 2ms, so like, G-Sync on always then. It's so crazy. The "critical framerate" where G-Sync off starts being "worthwhile" is 333.33fps So like on 360hz monitors with a locked framerate, maybe. Even then, it's not a 100% chance of it being faster. And if there's any dips, you can say adios to smooth game world state pacing. Motion is just so much clearer when the pacing of the GPU renders are displayed at the same pace on the display.