I just switched to Neon from Ubuntu Gnome and so far everything has been great except for gaming performance. On Ubuntu Gnome everything was playable with the Obiaf ppa at least 60. Even games like CIv 6 were working almost maxed out on the open source graphics. Right now with the same settings I'm getting around 10 to 25 fps in some games. For example Hearts of Iron 4 which ran flawlessly on my previous install is running at 7 fps now. For the life of me I can't figure out what is causing this and I was wondering if anyone here might have some hints. I'm really enjoying the Plasma desktop so I would like to get this fixed so I can stay on Neon.

P.S. : Besides this everything on Plasma is amazing, I'm loving it so far.

Hardware:
i7-4770k
R9 290
Samsung 950 Pro

Hello,

Which version of Ubuntu Gnome did your AMD graphics card work well on? Was it before or after Ubuntu 16.04? I ask this because Ubuntu and AMD for some reason dropped fglrx (the proprietary graphics driver) at 16.04, or kernel 4.4 for before 16.04. So Ubuntu 14.04 with a kernel earlier than 4.4 probably would have performed a lot better with your card than anything based on Ubuntu 16.04 (like KDE neon). You can try the recommendations here https://help.ubuntu.com/community/RadeonDriver to see if it makes any improvement.

When 16.04 came out, I switched to NVIDIA because of the AMD issue with supporting their cards on linux, since my kids are into minecraft and Civ and the open source drivers weren't good enough at the time.