I’m running CachyOS, and having an Nvidia card, I’m using their Nvidia-specific kernel. I know this 3060 won’t last forever, and I’m planning to upgrade to an AMD card for a better overall experience.
Is there anything I should be aware of regarding the kernel or other compatibility when switching brands? Can I simply plug in the new one and run pacman -Syu?
Sidenote: I will plan around my PSU’s output, so no need to advise regarding physical compatibility.


I can offer some distro-agnostic observations . . .
Having swapped from one to the other some time ago on Gentoo, what I had to (re)install was the kernel (since I’d built it without those drivers), mesa, and some xorg-drivers stuff (which may not be relevant to you). Also, LLVM (ugh), because the AMD drivers compile stuff on the fly somehow and gcc doesn’t have a usable AMDGPU backend. Or something like that. At that point, the system should boot well enough to bring up the GUI, and you can worry about vulkan and such after that. If you have an initrd, that may need to be rebuilt or replaced. Bootloader should be fine if it’s the same kernel version.
Having the kernel drivers for AMD present in a system with an nvidia card shouldn’t present any problems—without the hardware, the kernel won’t even try to load them. In theory, you should even be able to have both cards in there at once (if your mobo has the slots) and blacklist the drivers for the card you don’t want to use, but it isn’t the safest thing to try.
Thanks, and that’s what I was thinking might be the case. CachyOS has an easy tool for switching kernels, and I have a vague memory of needing to blacklist certain parameters during boot, but I’ll have to look into that more. Somebody kindly shared a migration guide link elsewhere to look at, and I bet it talks about some of the things you’ve mentioned.
Hopefully I can get away without a reinstall!