i just bought a "R9 280x Sapphire Toxic" 3 Years ago, and all was fine. it works with my rig and yeah..
after a while, some artefacts popped in, and they just disappear if i restart the game or computer.
i dont know how to fix it, i asked google and i'm not alone with this artefacts.
i think its a technical issue in the 200s Series from the R9.
is there any support to get a new one or fixes?