Poor performance on external HDMI monitor

NVIDIA Open GPU Kernel Modules Version

580.95.05

Please confirm this issue does not happen with the proprietary driver (of the same version). This issue tracker is only for bugs specific to the open kernel driver.

• I confirm that this does not happen with the proprietary driver package.

Operating System and Version

Fedora Linux 42 (Adams)

Kernel Release

Linux fedora 6.16.8-200.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Sep 19 17:47:18 UTC 2025 x86_64 GNU/Linux

Please confirm you are running a stable release kernel (e.g. not a -rc). We do not accept bug reports for unreleased kernels.

• I am running on a stable kernel release.

Hardware: GPU

GPU 0: NVIDIA GeForce RTX 4050 Laptop GPU (UUID: GPU-2ca17e95-0022-2199-f652-c9492f7926fc)

Describe the bug

When using an external monitor connected via HDMI, performance is much lower than expected. The monitor is a 2K 144 Hz display on HDMI, but framerates are capped well below the refresh rate (typically 40–80 FPS). The internal laptop panel runs fine at its native refresh rate, so the issue only appears on the external HDMI display.

https://github.com/NVIDIA/open-gpu-kernel-modules/issues/650

To Reproduce

Laptop: Acer Nitro V15 (ANV15-51) with Intel + NVIDIA GPU
External monitor: LG Ultragear™ 32GS60QC, 32", 2560 x 1440 1000R Curved, 144 Hz on HDMI input)
Connection: HDMI cable from laptop HDMI port to monitor
OS: Fedora 42 (Wayland, KDE Plasma 6.4.5)
NVIDIA driver 580.95.05

Steps to reproduce:

1. Boot laptop with the external monitor connected via HDMI.
2. Display configuration set to external screen only.
3. Launch glxgears, or testufo.com from browser.

Bug Incidence

Always

nvidia-bug-report.log.gz

nvidia-bug-report.log.gz
nvidia-smi-q.log

More Info

Expected result:
Framerate should reach close to the monitor’s refresh rate (≈144 FPS).

Actual result:
Framerate is significantly lower (≈40–80 FPS), fluctuating but never reaching 144 FPS.

Start by reviewing the linked issue #650 and the attached nvidia-bug-report.log.gz and nvidia-smi-q.log, then reproduce the problem with the listed Acer, RTX 4050, HDMI, Fedora, Wayland, and KDE setup using glxgears or testufo.com. Done means identifying and addressing the cause of the 40–80 FPS result so the external 2560×1440 display approaches its 144 Hz refresh rate.