I have a samsung tv that can run 4k@120hz. When I try to run it on Fedora (Gnome Wayland), it tries to switch to it, fails, and then switches back to 4k@60hz.
Please note that I am running integrated graphics Intel Iris (Xe) and the CPU spec says it supports 4k@120hz. Also, I am using a HDMI to Thunderbolt cable. I can run 4k@120hz on Windows just fine.
Is there any reason why fedora can’t run this mode?
Do you have an AMD graphics card, and are you using HDMI? If so, that isn’t going to work. HDMI is a closed standard, and AMD can’t implement it fully in their open source drivers. This prevents you from using 4K at 120 Hz over HDMI with AMD graphics cards on Linux. If you’re lucky enough to have a TV with a DisplayPort (which is an open standard) connection, use that instead. If not, I don’t know if there’s anything you can do in this case.
I am running integrated graphics Intel Iris (Xe). And the CPU spec says it supports 4k@120hz. And I can run it on windows.
Also, I am using a HDMI to Thunderbolt cable.
This likely means the kernel driver does not include some proprietary bits that are masking the capability from Fedora.