DirectX 12 will allows the use of Nvidia and AMD GPUs at the same time, rumours claim

It may not be one of its headline features, but an intriguing rumour concerning Microsoft’s DirectX 12 suggests that users will be able to use wildly different graphics cards in unison.

Currently both Nvidia and AMD allow owners to use two or more GPUs in tandem using their SLI and CrossFire technologies respectively. Such use is often beset by problems, however.
Not only do games rely on specific driver support to make the most of SLI/CrossFire, but the nature of how resources are shared can often lead to a host of other complications – all of which effectively mean that in the vast majority of scenarios a single card is the better choice.
However, Tom’s Hardware reports that a new Windows 10 API (presumed to be DirectX 12) will offer a brand new approach to asynchronous multi-GPU usage that more effectively pools all available graphics resources into a single computational pot.
Doing this eliminates the use of alternate frame rendering (AFR) which sees multiple GPUs taking turns to render each frame. One result of this is that both cards have to have all available texture and geometry data available and ready in their frame buffers – so two 2GB cards, for instance, still only have access to 2GB of data rather than, as is often presumed, the combined 4GB.
DirectX 12, it is claimed, will instead use a method called split frame rendering. This allows developers to divide data between cards as they choose, using all of the available resources to their fullest, leaving each card to assume particular duties independent of the other.
While SFR is not new in and of itself, the idea that users would be able to simultaneously run graphics cards from different manufacturers with entirely different architectures is unheard of.

http://www.mcvuk.com/news/read/direc...-claim/0145881