Possible graphics card upgrade

I have been playing Ashes for a few months now with a friend of mine.  I went out and built a new gaming PC specifically for this game.  My friend gave me an Gigabyte Nvidia 1060gtx 6gig graphics card for free.  The game plays fine, but I have to turn the settings down to get some good FPS.  I wold like to run the game a crazy setting, but when I do play at crazy setting, my Fps lowers down to the single digits. It can get unplayable at times.  I was thinking about buying a new graphics card and would love to hear your opinion on going with AMD and using Vulkan as the API.  Does this game run better on a AMD with Vulkan?  Or keep with Nvidia and use DX12?  

with this said, I was also contemplating buying a second identical GeForce 1060 graphics card and enabling the MGPU in the game settings.  These cards are super cheap and I can find one on EBay for nothing.  I have the horsepower for multiple graphics cards.  

Here are my specs.

AMD Ryzen 2700x 8 core 16 thread

Gigabyte B450m Aorus motherboard

32gigs of Corsair Vengeance LPX memory

1tb NVME SSD drive

Gigabyte GeForce 1060xt  6gig graphics card