Nvidia Reflex causes stuttering

[Solar Field]

So, I've been playing for a couple of hours so far and something was driving me crazy.

Basically the game runs at a locked 60fps (with ~55fps 1%low), but it never felt smooth. Every time I was moving the camera I could tell something was wrong, it was a stutter mess.

After spending an hour testing each option, I finally realised that turning off Reflex entirely fixed the problem. My game is finally smooth.

If MSI Afterburner (or any other app you're using to monitor your framerate) is reporting 60 (or your target framerate) but still doesn't feel like it, I would suggest to turn Reflex Off.

Other than that, the game runs very well and feels properly optimised (at least for my modest 5700X with an RTX 4070).

Enjoy o/

Edit: All drivers up to date (551.86), VRR display and G-Sync On, frame cap via RTSS: 60fps

[xShadow-Dragonx]

4090 on plus boost feels bad and looking at system latency shows some crazy numbers with it off.... never before seen highs

anyway the first and second options seem best to me on being the second option, not counting off as an option.

[Solar Field]

Originally posted by Kaldaien:

Originally posted by Solar Field:

Been using Reflex in many games and it never caused that issue.
So yeah, this is a problem.

Well, you can use Special K. Its framerate limiter will auto-configure itself to 99.5% of Reflex's internal limit so as to frame pace the game without hitting Reflex's limit.

The equation to calculate that limit is (a really weird one):

Refresh Rate - (Refresh Rate * Refresh Rate) / 3600.0

That's Reflex's target rate, you need to multiply that by 0.995 to calculate the limit to set a third-party limiter to in order to have it take precedence over Reflex.

You can certainly do all that crap by hand and plug those numbers into RTSS, but Special K makes it a hell of a lot simpler and has numerous Reflex-related overrides and analysis in the Framerate Limiter / Advanced section of its control panel.

For example, here's a game with an actual Reflex bug (has to be set to Boost mode manually or overridden in SK's override section):

https://youtu.be/2kK_OYHh2hY

Appreciate your time but I don't think that's the issue here.

Been using Reflex on Flight Simulator and CP 2077 without any problem. I don't understand why it causes such a bad stuttering in Horizon...

That said, I can't stress enough how well optimised this game feels to me. It runs very well on my end, no crash, no weird behaviour. But this Reflex thing is, I believe, not normal and it took me a while to figure it out.

Hope it will help those with the same issue, cause I do believe there is something wrong here.

[Emig5m]

Yea I found that having reflex off was smoother as well and I get a few frames faster performance. However, its in conjunction with having vsync disabled. Some games play better with it on, some off. For this game reflex/vsync off with DLAA native res looks and plays the best for me. The joy of the PC to try different settings to see which work best for you.

[Solar Field]

Vsync is on for me (as it should be when using G-Sync), but from NVCP. Ingame Vsync is off.
But this reflex issue is "interesting", to say the least.
Glad it worked for you too!

[ReliableEyball]

I've been running this game fine with the Latency Measures Only reflex setting and have had rock solid frames and times. Excellent smoothness until today when I'm getting big frametime fluctuations causing major stutter. Turning off reflex doesn't fix it either :(
No other game does it

[xShadow-Dragonx]

so i was playing overwatch today and man was it smooth at 120fps then i came and played this...

[Kaldaien]

Originally posted by xShadow-Dragonx:

so i was playing overwatch today and man was it smooth at 120fps then i came and played this...

Well yeah, you need a framerate limiter.
I run the game on my 4090 capped to 90 FPS at 3440x1440. It would be god awful if I didn't have a framerate limit set, and the options available in-game are just ♥♥♥♥. Use a real framerate limiter.

[nas360]

Reflex messes with VRR monitors in the game. If you have a monitor that shows the VRR frequency in Hz then you can do what I did to check how it is working.

With Reflex set to ON, the judder is 100% noticeable and my monitor's OSD counter fluctuates between 80Hz- 165Hz. Setting it to OFF fixes the problem and my Monitor's refresh rate counter become stable at around 78Hz-82Hz without jumping to 165Hz intermittently.
Setting the Reflex to On + Boost is better than just reflex ON since it improves the smoothness but slight judder is sometimes present. Frame gen forces reflex ON so there is no way to get past that problem unless someone knows how to force it off.

[Klyuch]

Can anyone explain why Reflex is needed? The game has as many as 3 settings, including complete disabling. What is the difference? What does "Latency measurement only" mean?

[EricHVela]

I only experienced issues with Reflex+boost but not Reflex without +boost. Then again, I'm using studio drivers for development and +boost tries to use shortcuts that aren't kosher with studio drivers.

(Game Ready drivers keep giving the device-disconnected error when developing apps.)

[sonycman]

Exactly the problem for me, reflex enabled causes stutter when rotating the camera, even without the boost.
Solution is just disable it completely.

RTX4090 with the latest drivers, vsync on, 60 fps.

[SilentHorizon]

Its not just Reflex, there's some underlying problem with mouse input in the game engine.

If you cap your frame rate at all, to the point where your always hitting that frame limit, you'll notice slight hitching in mouse movement no matter what.

The only way I've been able to not have mouse issues at all is to disable Reflex, enable in-game V-Sync, and make sure the game never touches my max refresh rate. Then the frame pacing is actually perfect, literally. For some reason this game prefers being fully loaded on the GPU side.

An easy way to tell this problem is by moving your character around with just your keyboard, and referencing the frame pacing from that movement, to movement by just moving the mouse.

[SilentHorizon]

Originally posted by Klyuch:

Can anyone explain why Reflex is needed? The game has as many as 3 settings, including complete disabling. What is the difference? What does "Latency measurement only" mean?

Latency only mode is a monitoring behavior of Reflex, in this mode Reflex is disabled but it will monitor system latency for you to see in the GeForce Expereince/Nvidia App OSD.

Reflex when it works correctly is designed to reduce system latency. When it works, its fantastic, and should be enabled, since its free performance for lack of better words.

Reflex makes sure that the CPU and GPU pipelines aren't "clogged" so to speak. Its basically an optimization on the back end.

[4dri3l]

same gpu/cpu, same problems. Reflex on or frame gen on, makes the game microstutter a lot. Without it, the game looks super smooth.

[Kaldaien]

Originally posted by Klyuch:

Can anyone explain why Reflex is needed? The game has as many as 3 settings, including complete disabling. What is the difference? What does "Latency measurement only" mean?

It's for reducing latency on VRR monitors.

Ideally when you use Reflex, you also combine it with a framerate limiter capped to your highest stable framerate. If you don't do that, you're not really using Reflex correctly and of course it's going to stutter.