The weather forecast for hell is snow. And, yes, those are pigs taking flight. Indeed, one of the most unthinkable events in PC gaming is underway thanks to DirectX 12: GeForce and Radeon cards can run side-by-side in a single PC.
The long-touted, but not quite public feature in DX12 that makes this possible is Explicit Multi-GPU. It lets games parcel out graphics chores to any GPU that supports a multi-GPU mode.