Hey !
I’ve encountered the same issue with Arc Raiders.
My setup is CachyOS with KDE Plasma on Wayland, an RTX 4070, and a MSI MPG ARTYMIS 323CQR (1440p, 165Hz, FreeSync) connected via DisplayPort. I tested both NVIDIA 590 and 580 drivers and got the exact same behavior.
At first, the game felt noticeably less smooth than on Windows, even though the FPS counter looked fine. It had that classic “FPS are high but it doesn’t feel fluid” issue. Then I started testing VRR (Adaptive Sync), and things got weird. Enabling VRR immediately made the game feel much smoother, so clearly frame pacing was involved. However, as soon as VRR was active at high refresh rates (144Hz/143.91 or 165Hz/164.55), I started getting very obvious visual issues: vertical bars, flickering, and what looks like unstable brightness or gamma shifts. In some cases, it even felt like ghosting.
I tried quite a few things to isolate the problem: FPS limiting with MangoHud and VKD3D, using gamescope, tweaking settings, and even switching between different NVIDIA driver versions. None of that fixed it. The issue was always the same: without VRR it feels stuttery, with VRR at high refresh rates it becomes visually unstable.
The only thing that actually solved the problem for me was enabling VRR and lowering the monitor refresh rate to 120Hz. With that setup, the game is smooth, there is no flickering, and the visual artifacts completely disappear. It’s not ideal since the monitor is capable of 165Hz, but in practice it feels much better than a broken 165Hz VRR experience.
So at this point, this doesn’t look like a performance issue or a Proton issue. It really feels like a VRR-related problem at high refresh rates, likely involving the Wayland + KWin + NVIDIA stack, possibly combined with how this specific monitor handles FreeSync. Under this malware that is Windows, 165Hz VRR works perfectly fine on the same hardware. Shame.
If anyone has found a way to make VRR stable at 144/165 Hz on Linux with a similar setup, I’d definitely be interested.