I have Windows 10 and two graphics cards 290х and 270х , can I use them together in Direct X 12, or only possibly use cards amd and invidia together.
If the game supports explicit multi adapter, maybe. So far only one game has implemented this technology and it's called Ashes Of The Singularity. The developers of that game recommend pairing GPUs will similar performance for the best experience.
More info here: DirectX® 12 for Enthusiasts: Explicit Multiadapter
I tested in 3d mark and Warhammer total war, second card was simply inactive.
Neither of those applications support explicit multi adapter, so that's expected behaviour.
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