Hi i new to fedora and i watched many guides and tutorials but i want to make sure im not missing anything some say to install custom kernel like tkg or cachy os and some say to install mesa-git so i just want to know what should i do to get the best gaming experience on fedora 40 kde with i7-14700k and amd 7800xt gpu.
Thank you
IME the best and safest route is to install fedora then add steam from the rpmfusion repo and little to nothing else. The more complex the config the harder it is to make things work properly.
CachyOS has caused problems for many as you can tell with the topics here. Custom kernels seldom gain anything and also seem to ensure that proper updates often have problems.
I would recommend GNOME with Xorg session for the best experience. Wayland is iffy, and KDE on Fedora’s Xorg support is questionable. YMMV 
With this report, I’d also force high-performance on the AMD GPU. I put that in a script and I press a keyboard shortcut to do it whenever I plan on playing a game.
And for general best gaming experience, disable all power-saving possible in BIOS, disable ASPM, ideally disable Hyperthreading (or benchmark it first), and make sure everything is running at ideal PCI-E speeds (something like the GPU possibly needing a specific motherboard slot for X16, or else X8 anywhere else).
My mileage says that fedora kde wayland with rpmfusion steam is a great gaming platform. I have amdgpu.
Dota 2 on Fedora 40 KDE (Plasma 6 Wayland) lost 10-20 FPS vs GNOME on Xorg on UHD 630 for me. On openSUSE TW’s Plasma 6 with Xorg, disabling the compositor brought performance up a bit.
On a few OpenGL games I also get an inexplicable ~50 FPS cap from GNOME/Plasma Wayland, that I tolerate working around by forcing those games to Zink (OGL is ~50 but OGL → Vulkan works fine). I’m not sure if 50 is a magic number or just what my hardware happens to get to (screen refresh rate is 60 or 75), but I don’t have this happen from Xorg sessions.
And with Titan Quest AE just a few days ago I had to do a cursor safe-mode workaround on Wayland that made the cursor feel a tiny bit more-floaty. Without the fix there was no cursor. Cursor shows and performs well without the workaround fine on Xorg.
Basically, I’m not sure what Wayland is still trying to solve without causing weird issues in the meantime.
I do not see that cap. But I do not play the games you are so comparison is hard.