RealNC wrote:There is a solution for this, but it's up to nvidia to implement it. When the maximum G-Sync frequency is equal of less than the monitor's maximum frequency, then g-sync should display the same frame twice every time, doubling the frequency.
For example, in a 144Hz monitor, if you set "72Hz doubled" as the G-Sync mode (obviously it doesn't exist right now), then games that render at 30FPS will have a 60Hz mouse cursor.
It could also be possible to do this every time without having to manually configure anything. For example, if the framerate falls below 60FPS, then g-sync could use frame doubling anyway. But there's problems because of quick framerate fluctuations, which means that this approach would increase input lag if g-sync is currently displaying a the second duplicate frame but the GPU has a new frame ready which now needs to wait (so you're in a v-sync situation.) So this can only work reliably when using a g-sync max freq that's below the max monitor freq.
Actually that's already happening according to PCPer, at least below 30Hz. That's what they wrote in their FreeSync review from last week:
http://www.pcper.com/reviews/Displays/A ... e-VRR-Wind
But what happens with this FreeSync monitor and theoretical G-Sync monitor below the window? AMD’s implementation means that you get the option of disabling or enabling VSync. For the 34UM67 as soon as your game frame rate drops under 48 FPS you will either see tearing on your screen or you will begin to see hints of stutter and judder as the typical (and previously mentioned) VSync concerns again crop their head up. At lower frame rates (below the window) these artifacts will actually impact your gaming experience much more dramatically than at higher frame rates (above the window).
G-Sync treats this “below the window” scenario very differently. Rather than reverting to VSync on or off, the module in the G-Sync display is responsible for auto-refreshing the screen if the frame rate dips below the minimum refresh of the panel that would otherwise be affected by flicker. So, in a 30-144 Hz G-Sync monitor, we have measured that when the frame rate actually gets to 29 FPS, the display is actually refreshing at 58 Hz, each frame being “drawn” one extra instance to avoid flicker of the pixels but still maintains a tear free and stutter free animation. If the frame rate dips to 25 FPS, then the screen draws at 50 Hz. If the frame rate drops to something more extreme like 14 FPS, we actually see the module quadruple drawing the frame, taking the refresh rate back to 56 Hz. It’s a clever trick that keeps the VRR goals and prevents a degradation of the gaming experience. But, this method requires a local frame buffer and requires logic on the display controller to work. Hence, the current implementation in a G-Sync module.
This graph represents a scenario in a game where the frame rate is dropping over some amount of time, indicated by the blue line moving from right to left. It could be the gamer entering a very intense action scene, for example, with hardware that is seeing frame rates slowly dropping from ~40-50 FPS down to 10 FPS.
I made this diagram to demonstrate what we think is happening with G-Sync based on our testing. I should be clear that NVIDIA did not give us this information nor did it confirm if we are accurate or not. If correct though, as the game frame rate decreases it will double, triple, quadruple, etc. frame draws to maintain a draw rate over 30 Hz. There are interesting edges that occur with this method too though, including when to actually redraw an existing frame from local memory if another new frame from the GPU is "nearly" ready. It would appear that NVIDIA has been and will continue to tweak this algorithm in attempt to keep user experience optimal.
Is that in multiplayer or single player? I tried BF4 in single player for a little bit and the performance was the same but Gsync was working better. I still got a lot of engine stutters but I blame that on my 2GB Vram.