HDR+VSYNC causes stutters and visual artifacts/issues.

[dudfunk]

Vsync in-game or by Nvidia Control Panel plus enabling in-game HDR causes periodic stutters and sometimes odd visual artifacts. For example when at the main menu or if I have the console open, half the screen will show a black dot-matrix like texture for a few frames. The HUD is also affected. In game though, I don't really see any artifacts, but serious stuttering every few seconds. If I disable either VSYNC or HDR, problem is gone. I have HDR enabled in Windows, using 4:2:0 10bit on a Sony x900e and RTX 3090. Enabling/Disabling HDR in Windows Settings makes no difference.

[Calinou]

Can you record a video of the screen using a camera when the issue occurs and upload it here? Use slow motion if the issue is hard to discern in real-time.

Do other games in HDR exhibit similar issues in fullscreen? Also, are you using exclusive fullscreen or a borderless fullscreen window?

It may also be worth disabling Hardware-Accelerated GPU Scheduling (HAGS), as per #182. Note that disabling this feature will limit certain functionality in other games, such as DLSS Frame Generation which requires it.

[dudfunk]

https://youtu.be/RF4PVUevZl4

I did some more testing, and found that the issue occurs when HDR, Vsync, and resolution scaling are enabled, at 3840x2160@60hz, exclusive fullscreen only. I don't have HDR issues anywhere else, but I will say re resolution scaling, I've seen similar flickering in Cyberpunk 2077 while FSR dynamic resolution is enabled, regardless of HDR, and vsync.

Back to Quake, I did another test which threw me off. I set the resolution to 7680x4320@60hz (DSR), then enabled res scale with target 60fps, min res 50%, max res 100% (same as above). Did not see any flickering.

[dudfunk]

It may also be worth disabling Hardware-Accelerated GPU Scheduling (HAGS), as per #182. Note that disabling this feature will limit certain functionality in other games, such as DLSS Frame Generation which requires it.

I don't use FG since I have a 3090, so I will give that a try.

[Calinou]

Do you have variable refresh rate/G-Sync enabled? This could be VRR flicker, which is inherent to how monitor hardware works and can't be fully resolved. (Some monitors offer a VRR Control/Fine Tune Dark Areas setting to reduce the visible impact, at the cost of added input lag or worse contrast.)

Monitors need to change their gamma curve when the refresh rate changes, but since this can't be done instantly, you'll notice a flicker depending on a pixel's brightness. This is most noticeable at lower refresh rates and with wildly varying frametimes. On the other hand, if you have a relatively low framerate that is constant, the flicker may be invisible.

[res2k]

Actually, if you look closely, the whole UI - console and and HUD and the bottom - seems to flicker, which is quite weird ...
Those should be drawn every frame. I don't have an explanation for them disappearing.

You mentioned Cyberpunk 2077 + FSR. Do you have FSR enabled for Q2RTX? If so, maybe try without it. (Or if not, with it.)
It'd also be interesting to see if the issue persists if you use a different display, but I can understand if that may be hard to do...

[dudfunk]

Do you have variable refresh rate/G-Sync enabled?

I don't use Gsync, just plain old vsync.