Ive owned a 7870XT, R9 290x, aswell as an AMD 480. All three of these cards all had every one of those issues. Directx 9 seemed to help them but even then it would eventually start acting up again. I would often get disappearing characters, mobs, bosses, ect too. The longer my game session was, the slower my FPS was. It would always eventually freeze up if I kept playing beyond. I decided to grab an nvidia 980 last year and for the first time in 5 years, I haven't had any of these issues.

I always throught it odd that SE listed the recommended GPU for this game is either a ti-550 or an amd 7970. A 7970 isn't even in the same league. It's a billion times faster, so with that said, why would SE list such a high end card as recommended spec back then whe the nvidia card was weak?

A old cheap nvidia GPU will run circles around a high end AMD gpu on this game, so with that said, I would encourage those who play this game and are looking for a new GPU, Use nvidia and stand well clear of AMD.