VRR - how "smooth" should it be when fps fluctuates?

[buffeh]

Hi,

Tried and failed to find a solid answer to this. Posted on reddit but nobody replied. Would appreciate if someone could either tell me if something about my setup isn't right, or if I'm expecting perfection when maybe it just isn't possible.

So I recently got my first VRR capable display, a Sony A95L, and was excited to be able to get over 60fps without having to worry about screen tearing. I was coming from an older LCD Sony with no VRR and a 60hz panel. I game with a gaming PC connected to a TV. My PC is fast and currently has a 5090.

VRR is definitely enabled. I have GSync enabled in NVCP in both sections where it needs to be enabled. In Windows display settings it says I have a VRR capable display. I have tried with an FPS cap of 116 set in NVCP with Vsync forced on, and Vsync off in game, and I've tried setting an FPS cap of 116 in RTSS, seems the same to me. If I play a game and bring up the Sony Gaming bar I can see the hz on the TV changing as the FPS changes and the Sony TV seems to think VRR is working. As an extra check I tried with Special K and it said VRR was enabled as well. So I'm positive it's working. (Also I see no screen tearing).

My question is how "smooth" should something like panning a camera in a game be when FPS is fluctuating, between, lets say 90 and 116, and VRR is being used. An example for a recent UE5 game would be Silent Hill F. In the starting area, adjust the graphics settings and find a spot where simply rotating the camera in place (so all assets should be loaded) causes the FPS to fluctuate a bit between the max (116) and lower (ie 90 / 100). Standing somewhere with foliage on one side and a wall on the other can achieve this. If I do this I would say the movement isn't 100% smooth. I can see what I would describe as slight judder on the scenery when I pan the camera. Not so much like it's skipping frames, but more like the frames aren't all arriving at exactly the same time, ie the pan will sort of go fast slow fast slow as the FPS fluctuates.

I might be imagining it but this seems worse in UE5 games. I think it can still be observed in non VRR games as well, I think I can see it in Kingdom Come Deliverance 2 as well but it's less noticeable. But I'm pretty sure when I played Silent Hill F on my old TV at a locked 60fps, I didn't experience this slight lack of smoothness. So I know that this game CAN be 100% smooth on my PC. But this was obviously before I had any VRR display.

If something isn't working right I have no idea what I could do differently and honestly I might give up on VRR and play at locked multiples of 120 if I have to as I find the slight variance in speed / the slight lack of perceived smoothness quite distracting. It would be nice to know if what I experience is the same for everyone, but I have no idea what could possibly be wrong if it's perfect for others but not for me. If anyone else has Silent Hill F would be interested to know if they experience the same thing as me. Is it just not possible for something like a camera pan to be 100% consistent in speed when the FPS is fluctuating?

Thanks!

[buffeh]

I've done a lot of testing over the last few days.

I have a few recent UE5 games I've been using to test. Silent Hill F, Cronos, and Keeper. I also have a non UE5 game I've been using - Kingdom Come Deliverance 2.

With these settings: Gsync fully enabled in NVCP, VRR enabled on TV, 120hz, NVCP fps cap at 116fps. Vsync on in NVCP and off in game, or on in game only - tried it both ways for all games, couldn't really see a difference. TV (Sony A95L) game bar clearly shows the hz fluctuating as fps fluctuates as it should.

- Silent Hill F (UE5) - no tearing as VRR is certainly working. Panning camera in starting area has occasional stutter which seems worse when the FPS flucuates which at the settings I'm using is between 120fps and 100fps. Camera speeds up and slows down a bit as well
- Cronos (UE5) - similar to Silent Hill F - almost the same in fact. Frame gen is being used
- Keeper - can't pan the camera in this game but as you move if you look at distant objects when moving left and right you can see they don't have good frame pacing, they judder quite distractingly. Frame Gen is being used
Kingdom Come Deliverance 2 (CryEngine) - best of the lot, judder is infrequent but still happens very occasionally. The speed up / slow down effect when panning is still present when FPS fluctuates.

With these settings: Gsync fully enabled in NVCP, VRR enabled on TV, 120hz, NVCP fps cap at 100fps. Vsync on in NVCP and off in game. The purpose of these settings is to get a locked 100fps but leave everything else the same.

- The UE5 games are slightly improved but they still exhibit a degree of poor frame pacing. KCD2 is very nearly perfect. I can see the TV game bar showing the hz fluctuating between 95 and 105hz as of course VRR is still enabled.

With these settings: Gsync disabled for the specific games I'm using only (ie set to fixed refresh in NVCP), VRR enabled on TV, 120hz, NVCP fps cap at 120fps. Vsync on in NVCP and off in game. Game settings reduced to get a locked 120fps.

- Even better still but surprisingly not perfect. I was expecting this to be the same as not using VRR at all, but still saw the occasional stutter in the UE5 games at the very least. The TV game bar no longer fluctuates and stays on 120hz, but VRR is still enabled on the TV.

With these settings: Gsync disabled entirely (systemwide). VRR disabled on TV. 120hz, NVCP fps cap at 120fps. Vsync off in NVCP and on in game (mirroring the setup I used to use with my older 60hz LCD Sony). Game settings reduced to get a locked 120fps.

- Seems absolutely perfect. No judder or bad frame pacing when panning while standing in place. Any stutter at all is clearly UE5 compilation stutter as it doesn't happen when character is standing still.

The same is true if I set the panel to 100hz instead, which it has an option as a native PC mode. This is really handy as this means I can aim for a locked 100fps for games where I can't manage 120fps and don't want to settle for 60fps. I played hours of Cronos last night and didn't see a single stutter that clearly wasn't traversal stutter. Multiple times I kept stopping in place in game and rotating the camera and every time it was completely smooth frame pacing. Unlike a few nights ago when I played with VRR on, and it just wasn't as smooth.

Worth mentioning I did try a completely fresh Nvidia driver install (removed with DDU beforehand). I also tried a few other things such as disabling HAGS, nothing really made any difference - I just can't get what I consider to be acceptably smooth gameplay with VRR in use.

So I guess I'm posting this so either someone can tell me I'm not crazy and it's the same for them, or someone can tell me that no it should be absolutely as smooth as when not using VRR and having the panel refresh rate matching the fps, and something with my setup is wrong, and maybe they can suggest things I can try. I have seen a few users say they have stutter in other threads although usually it's because they've overlooked something. I often see a response given on these forums is "VRR can't fix poor frame pacing in games" and yes of course I fully accept that. But every game I've tested as an example has perfect frame pacing with normal vsync and panel refresh rate matching FPS, and worse frame pacing with multiple different VRR configurations.

Anyway if anyone happens to read all this would be interested to know their thoughts or maybe someone can kindly test some of the games I tried with the settings I tried to see if they observe what I did.

[RealNC]

VRR doesn't fix stutter. If there's frame time spikes (like in the RTSS frame time graph), then the game will still stutter, VRR or not.

What VRR fixes is the judder you get when FPS doesn't match Hz. For example if you disable VRR and cap your FPS to, say 70FPS (using NVCP or something like RTSS) while in 120Hz mode, then if you do a smooth camera pan in the game, you will see very small "hiccups" in the motion (we call this "judder".) If you enable VRR, then those hiccups shouldn't occur anymore. This assumes the game itself isn't stuttering. If it is stuttering, then nothing can help.

[buffeh]

I really appreciate your reply and I understand that my post was quite long and rambling so some of my details may have been lost but I do fully understand what VRR is meant to do and I did address at the end of my post that a common response given on these very forums is "vrr can't fix frame pacing" ie vrr can't fix stutter if the game stutters. But in all my testing the 4 games I've tried are all completely smooth without vrr, and exhibit noticible occasional stutter and inconsistent frame pacing with vrr, as I said in my post. I simply wanted to know if VRR should mean absolute perfection on a par with vsync and a locked frame rate, or not, as I've observed. I find it hard to believe there is something wrong with my setup, but I'm open to suggestions. But in my case "if it's stuttering, then nothing can help" simply isn't true, as disabling vrr entirely and going back to normal vsync fixes everything.

[RealNC]

It should be perfect is the FPS cap is perfect. The best FPS limiter currently is the one is SpecialK. But that tool is not suitable for everything (for example online games with anti-cheat.) RTSS and the Nvidia limiter (through the Nvidia control panel's 3D settings) should also give smooth results. If the cap is reached by the game, and the game also doesn't misbehave when FPS capped, then it should be perfect. (I've seen a at least one game that stutters when FPS capped, but is smooth when uncapped and only limited by vsync.)

In other words, if you cap to 60FPS with VRR enabled at 120Hz, it should look no different compared to running it without VRR at 60Hz with vsync enabled. (Other than possible OLED VRR flicker, that is.) If not, then indeed something is wrong. Like maybe the display just isn't very good at doing VRR.