Doom is an OpenGL game, Not Directx. Plus Vulkan allows the AMD cards to stretch their legs with the lower Overhead and higher draw-calls similar to what we see between DX11 and DX12.
Although as i said in my post, there are many reasons why AMD is behind in OpenGL performance.
I didn’t say it wouldn’t benefit AMD. I asked why would it even the playing field. Any advantage AMD get so do NVidia. Yes Vulkan was based on Mantle but Vulkan is not Mantle and far different from what Mantel was. I wasn’t aware AMD had poor OpenGL performance in comparisons to NVidia. I thought AMD had decent OpenGL performance so the playing field stays the same when swapping to Vulkan.Why wouldn't it benefit AMD. Mantle and DX12 are both low level api's and benefit AMD so why wouldn't Vulkan which is based on Mantle. In the op's results at 1080p Nvidia have a lead most likely due to amd's driver overhead. Under Vulkan this should not be a problem if it's coded properly. It's not a 100% that this will be the case but it's likely that AMD will gain some performance in Vulkan like they do in Mantle/dx12. With Amd's history of poor openGl performance Amd might even see a bigger jump in Vulkan compared to Dx11/Dx12