I'm running with the same graphics card and I can tell you that this is not computer related problem. Well, it is and it isn't. I started having this same problem after updating the windows 10 creator updates, and reason for the fatal dx error is somewhere in AMD drivers and new windows updates clashing.

When XIV introduced the dx11 support for the game, it took AMD around 9 months to fix their drivers so it doesn't crash with the game. Only fix right now is to run game in dx9 mode and hope AMD fixes this.