The Vulcan API has been rolled out which is based on AMD Mantle API and developed by Khronos. Along with DirectX 12 it is a next gen API. AMD are in partnership with DICE. So if you play EA games (which it has been optimised for), you will probably get a performance advantage using Vulcan on a similar spec GPU vs an Invidia GPU. Both Vulcan and DX12 have at least a  10 x faster Draw Call Rate than DX11

The API overhead really effects your computers performance Direct X 11 has a far slower draw call rate than Mantle which can cause bottlenecks due to the load imposed on the CPU . Trouble with Mantle though,is not a lot of games support it.  I use it on BF 4 and it really does improve FPS. This should change with Vulcan so it is available in more games I am 99% sure it will be available for Battlefield 1



Here is a brief promo video from AMD



This is the tech spiel I lifted from the dev website

Vulkan is intended to provide a variety of advantages over other APIs as well as its spiritual predecessor, OpenGL. Vulkan offers lower overhead, more direct control over the GPU, and lower CPU usage. Intended advantages include:
Reduced driver overhead, reducing CPU workloads.
Reduced load on CPUs through the use of batching, leaving the CPU free to do additional computation or rendering than otherwise.
Intelligent and even CPU scaling for multi-core CPUs, which are by far the majority type of CPU on the market. Previous APIs like DirectX 11 and OpenGL 4 were initially designed for use with single-core CPUs and could not easily use multiple or scale the workload evenly across them, leaving some CPU cores underworked and some not even utilized at all, resulting in performance issues and frequent CPU bottlenecks.
OpenGL uses the high-level language GLSL for writing shaders which forces each OpenGL driver to implement its own compiler for GLSL that executes at application runtime to translate the program's shaders into executable code for the target platform. Vulkan will instead provide an intermediate binary format called SPIR-V (Standard Portable Intermediate Representation), analogous to the binary format that HLSL shaders are compiled into in DirectX. This reduces the onus on driver vendors, allows shader pre-compilation, and permits application developers to write shaders in languages other than GLSL.
Unified management of compute kernels and graphical shaders, eliminating the need to use a separate compute API in conjunction with a graphics API.
Cross-platform API supported on both mobile devices and high-end graphics cards.
OS agnostic to improve the portability of applications created using the API.