Which card do you have? The latest open source drivers seem to be doing pretty ok. I can only tell you that with unofficial patches it works on Arch Linux with kernel 4.4. You should check with your distro installer instead of trying to do things manually.
sorry im using custom ubuntu 14.04.4 and the mobile apu a8-6410 r5. wanna use the 4.4.3 kernel and play pirates knights and vikings on steam with good fps. =p i can try and build the fglrx driver however it fails to build a module. fglrx says it only supports kernel 3.19 meh. i think i saw a thread on arch about someone getting it to boot with like a 4.2 kernel; however, i have trouble finding the files for amd x64 without pac man.
OpenSuSE is good too with sebastian siebert's patch, on Ubuntu you must play with oibaf and others repos, but they should work.