This is true. I have reinstalled tumbleweed because leap was unable to load kde. It also uses kernel 4.4, rather than 4.16. After reinstalling tumbleweed, I found out that the amdgpu driver is installed on it. Just not on the previous installation, because I tried installing wine+gallium from an external repository. It messed up my video drivers. Now I can run gallium nine in tumbleweed by using the wine from the default repositories. However, the gallium nine is having a problem with the game I want to play. Now that I have tumbleweed running, without gallium nine the game is running as fast as gallium nine on ubuntu.
I tried installing 18.04, it has the same performance problem with blender. I did retest blender to make certain it was not amdgpu, the performance in tumbleweed with blender is unmatched.