I am looking to buy the AMD Radeon Pro Duo. Is it possible to have the AMD card used specifically for Blender rendering while my Nvidia card is used for everything else (My monitors would be plugged into the Nvidia card)?
Short answer is Yes.
In the recent past I had a GTX 680 for rendering and R9 290x for gaming and all (this was before OpenCL support was fixed) and it worked as charm.
So setting up Radeon Pro Duo (nice purchase by the way) using OpenCL render, and Nivida for everythign else will work (and you should be able to mix both in some cases.
Thanks for the response Grzesiek! I was trying to figure out if I should get the Radeon Pro Duo or get a second gtx 1080. I wasn’t able to find a good answer to whether Blender would render using that secondary gpu (the AMD) while my current 1080 is the dedicated gpu.