[Ray88]

Since when have we disregarded direct x series? DX12 is the future whether you like it or not.
Considering AMD has put in a massive amount of R&D into DX12 with supporting applications such as vulkan, mantle, and async compute i only see AMD getting better.

The main reason xfire/sli was bad in dx11 was because they used alternate frame rendering (AFR) which caused latency between the communicating gpus as frames were queued one after the other which notoriously caused micro stuttering. Basically the two gpus communicated between each other acting as ONE gpu.

Split frame rendering (SFR) on the other hand (implemented into dx12) causes each gpu to focus on a specific region of the screen and act independent of each other, dramatically decreasing latency. One gpu would be designated for the left hand of the screen while the other gpu for the other half of the screen.