Terrible stutters when using Windows Dynamic Refresh Rate (DRR)

[WrobotGames]

Tested versions

Tested on v4.4.1.stable.steam [49a5bc7]

System information

Godot v4.4.1.stable (49a5bc7) - Windows 11 (build 26100) - Multi-window, 2 monitors - Vulkan (Forward+) - integrated AMD Radeon(TM) 760M (Advanced Micro Devices, Inc.; 32.0.13031.3015) - AMD Ryzen 5 7640U w/ Radeon 760M Graphics (12 threads)

Issue description

When using the Dynamic Refresh Rate feature in windows enabled on one or more monitors in your setup Godot stutters every time the mouse starts or stops moving, if Godot is running on an high refresh-rate external monitor.

100ms stutters make the game, or even the editor feel really bad.

What is Windows DRR? Windows DRR is a feature where Windows only uses the high refresh-rate (like 120hz) when the mouse moves, and when the mouse is not moving it uses something lower, like 60hz to save some power. To use drr, vrr needs to be enabled on a monitor.

Where I noticed this issue:
My laptop has a vrr screen, and to save battery I use the drr feature. Godot never stutters on the internal screen, whether drr en enabled on the internal screen or not. The problems show up when I started using an external high refresh-rate screen. When using drr on any of the screens, Godot stutters on the external display, even if this display is not vrr. Godot does not stutter if drr is disabled on all screens.

My laptop has an AMD gpu, I will test this on a Nvidia gpu in a few days if needed.

Steps to reproduce

1. Enable windows DRR on any screen. (A recent version of windows 11 is needed and a vrr display.)
2. Open any project in playtesting and use the profiler to see the stutters everytime you start and stop to move your mouse.

The screenshot is in Dutch, but it is the blue toggle under the refresh rate option in the windows settings.

Minimal reproduction project (MRP)

Any project will do. Even an empty scene.

[Calinou]

Don't use VRR on the Godot editor to avoid this issue. NVIDIA G-Sync is only enabled by default on fullscreen games by default for this reason, and we use a NVIDIA profile to disable it in windowed mode. Unfortunately, AMD has no equivalent API for us to use.

[WrobotGames]

This happens in an exported game as well, though, even in exclusive full-screen. VRR isn't really the issue either, it is just when I enable the DRR in the windows settings the editor, and exported games start stuttering. Using VRR without DRR is no problem.

I'll check how this works on nvidia when I get back to my pc in a few days.

[Calinou]

Can you reproduce this after switching rendering_driver/name.windows to d3d12 in the Project Settings, then restarting the editor? Also check if you can reproduce this after switching to the Compatibility rendering method.

Lastly, try setting Vsync Mode to Disabled in the Editor Settings.

[WrobotGames]

I can confirm that this issue also exists on nvidia gpu's, in DirectX 12 and without vsync. It feels less buggy though without vsync, as Godot doesn't try to cap the frame-rate anymore, but the stutters are still there. (On a side note, DRR feels really bad in the entirety of windows on desktop, almost everything lags.)

It also stutters in compatibility mode, but this does not show up in the profiler when not using vsync. When using vsync the profiler looks like this:

I have checked other game engines and unreal also does not perform well either, it basically locks the game to the lower refresh rate, meanwhile unity does not seem to have any issues, even though the game I tried hasn't been updated in years.

If there is no easy way to solve this, like some windows api forcing the highest refresh-rate, I don't think a lot of time should be spend on solving this, as this is a fairly obscure issue and other games suffer as well.

[andrebrait]

Well, I also experience stuttering on the desktop with DRR enabled (NVIDIA RTX 5070 Ti on an Ryzen 9 5800X3D here), so I'm pretty sure it's not engine-specific.