After 12 years of AMD refering to their two or more AMD GPUs running at the same time as Crossfire, they’ve made a branding decision and they now call it mGPU or Multi-GPU.
Basically, it is still the same as Crossifre where you can use both of your identical AMD GPU to play games, for rendering works and among others. But this time, it will be in the hands of the developer as they can use Direct X 12 or DX12 to accomplish.
DX12 in and of itself does not rely on the proprietary SLI and CrossFire technologies that NVIDIA and AMD have developed. DX12 multi-GPU support stands on its own two feet. All that’s required of the vendor is to make sure that their hardware and software is compliant with the multi-GPU features built into DirectX 12. This is why AMD isn’t calling multi-GPU support in its latest driver release CrossFire, because it simply is not. Not anymore.