I am looking for a graphics card that works well (i.e. has good performance) with the open source drivers that are part of the Linux kernel (version 4.2). I don't need monster performance (not interested in gaming at all) but at least the desktop environment (GNOME Shell) and WebGL in the browser should work smoothly. Cost should be €100 or less.
I have done a lot of research already but now once again bought a graphics card (Radeon HD 8350) that exhibits showstoppingly terrible performance (8 FPS on simple WebGL benchmarks) with the open source Radeon drivers. It's easy to find GPUs compatible with Linux nowadays (which this one is) but in practice it's still unusable without the binary blob.
I know that Phoronix is considered the authoritative source on that topic but they mostly test high-end GPUs for which they consistently find abysmal performance under Linux compared to the proprietary drivers. I just need a card that will make my desktop and browsing feel like it's 2015 and not 1992.