I've got a R9 270 card, and I'm using Ubuntu Mate 14.04, with two monitors setup.
I'm on fglrx since 12.04, I think some 14.x version of fglrx, and aside from poorer performance than in Windows, I had no major issues. However, since the latest 14.x update and the 15.5, even the simplest games are choppy and tearing in the upper half of the screen. This was not the case earlier, and it shows whenever there is some sort of scrolling. Most of the games are virtually unplayable. If vsync is forced, the tear is reduced, but the overall performance drops significantly. One of the obvious examples are 140, Guacamelee, etc. More demanding games are out of question.
I've recently reinstalled the OS, and the drivers, without success.
I've got no problems in 2D, though.
I'd appreciate any suggestions.