I currently have a MSI Radeon HD 7790 - however it does not work very well on Linux (TF2 barely like 20FPS on proprietary drivers).

I'm looking to replace it with another card - and I'm not against downgrading since I only play old games and a couple of non-intensive ones (rarely, gaming is really not my priority).

My absolute top priority is that support for all those various features is great, comes out of the box, and everything on the Linux desktop is smooth. Obviously, it would be great if it had better 3D support than my current one - so at least it could run TF2.

Essentially I want it to be smooth and hassle free - but still good performance for gaming at least from time to time.

Which card should I get?

I have no preference over NVIDIA or AMD, and no preference when it comes to open source or closed drivers (as long as they're all easy to install and work well).

Motherboard: M5A97 EVO R2.0
Processor: AMD FX-8320