Stutter with driver-forced vsync and Nukem FG

[aufkrawall]

Usually, natively implemented FSR 3.1 FG works well with driver-forced vsync with HAGS on and no overlays injected.
However, when selecting Nukem mod in OptiScaler, there are bad render or present stalls all the time, i.e. bad stutter. It also happens when forcing Reflex off in fakenvapi. It doesn't happen with OptiFG (or Uniscaler). I've tested this in Witcher 3 with latest builds available. Would be nice if this worked, as fps limiters can't guarantee 100% absence of tearing, which vsync does. This is on Windows 11 24H2 with RX 9070. If I recall correctly, this issue also exists on Ampere GPUs when using DLSSEnabler for FSR FG. Edit: I think it doesn't happen with just using purely Nukem mod on RTX 3060 without fakenvapi and OptiScaler.

Debug logs of OptiScaler, fakenvapi and regular log of Nukem mod:

logs.7z.zip

[aufkrawall]

I think the stutter with vsync and Nukem mod is more of a symptom than a cause, as without vsync, there also is much more tearing with Nukem mod vs. OptiFG. Haven't yet checked if this also reproduces like that in other titles.

[aufkrawall]

OptiScaler with Nukem FG + driver vsync works well in The Talos Principle: Reawakened Demo, so not a general issue. Maybe related to StreamLine, as Witcher 3 ships ancient 2.1 version which also can't be updated/replaced?

[TheRazerMD]

This might be a per-game issue also, as DLSS FG used to block Vsync from being enabled at all (which might interfere with Nukem), not sure how it is today.

[hellypi]

I also noticed stutters in witcher 3 and cyberpunk 2077 with framegen (nukems) on a 9070XT. Can you check the two videos I posted in this issue ( #422 ) and see if it's the same with you? Hopefully your monitor also allows real time framerate viewing. Also can you record your screen so I can see if we have the same problem? Maybe we could figure out a combo of settings that work

Someone mentioned turning off HAGS but it didn't really help me