[Alsa, no sound]

I am also having sound problems, so hopefully I can try some of the steps above..since my input shows only Dummy Input.

[installing X with radeon driver lead to llvmpiped slow X]

Hey, I was able to fix it by changing VIDEO_CARDS="radeon" to VIDEO_CARDS="radeonsi". I found the solution on a Gentoo forum:

https://forums.gentoo.org/viewtopic-p-7534494.html

 

The instructions that I followed:

"Make sure you have VIDEO_CARDS="radeonsi" and then `emerge -N media-libs/mesa` again; to be save `emerge -N @world` might also be a good idea to rebuild other libraries that use VIDEO_CARDS too."

 

and after it recompiled x server, llvm, and etc, it worked :D and I can play Steam games, and my DE is accelerated.