I own a Lenovo P15 Gen 1 with RTX 4000 and have problems using an external monitor. I’m using the newest Fedora Silverblue version (kernel 5.9.14-200.fc33.x86_64) and Nvidia drivers (modinfo Nvidia version: 455.45.01). My 5k monitor is connected to the laptop using a thunderbolt 3 cable. I noticed that app which are displayed on the 4k display of my laptop are snappy whereas app displayed on my 5k monitor are displayed much more sluggish. The animations for example when clicking the „Show applications“ button are much smoother when displayed on the internal laptop monitor.
I did the following investigations:
- The same apps running in a windows WSL2 and displayed via VcXsrv XServer are running smoothy without lag and without loud fan noise
- Without Nvidia drivers and when using Wayland I have lots to problems. The external monitor is not displayed in the settings. With discrete graphics enabled I can not boot at all when the monitor is plugged in.
- With Nvidia drivers, hybrid graphics settings in bios and X11 I can use my monitor with 5k resolution. But I have the performance problems described above. The fan noise is ok and not louder than using windows and wsl2
- With Nvidia drivers, discrete graphics bios settings and X11 it I have other problems. The performance problems are gone, all is displayed smoothly. But there are other problems. Sometimes there is an offset between the two display halves in the middle of my external monitor. Every time there is a vertical line where the pixels are blurry. It is as if there is an offset too and the pixels color toggles between the color of the left the right side. It is not recognizable immediately but only if you look at a horizontal line in an application. But it is very annoying of there are two of these offsets (one in the middle and one blurry line on the right side).
- Using discrete graphics if I close notebook so that only the external monitor is used, the problem with the pixel offset disappears. Better thann nothing, but I would really like to use the two displays (external + internal monitor)
- Using hybrid graphics if I close notebook so that only the external monitor is used, the system gets unusable slow.
This drives me crazy. Because it works seamless when running the same apps in windows wsl2 with my monitor, I don’t want to buy new 4k monitors which might be more compatible with fedora. Any suggestions tipps how I can solve my problem?
P.S.: Posted the same question in the lenovo forum: https://forums.lenovo.com/t5/Fedora/External-monitor-with-slow-performance-or-not-working-at-all/m-p/5056029