Microsoft DirectX 12 is DirectX 11 with Mantle Integrated

Sources have revealed that Direct X 12 is basically DirectX 11 with Mantle absorbed, the performance increase on Xbox One is in doubt.

NVIDIA GeForce GTX 980M - DirectX 12 benchmark and all you need to

Windows 10 Technical Preview Gets DirectX 12

Compare DirectX 12, Mantle and DirectX 11 with 3DMark

DirectX 12 vs. Mantle vs. DirectX 11 CPU & GPU Benchmark

NVIDIA releases first DirectX 12 Ultimate driver for developers

Mantle vs DirectX 11 - - Gamereactor

Can I install DirectX 11 instead of DirectX 12 in Windows 10

The DirectX 12 Multiadapter Concept Isn't Really New - PC

Microsoft DirectX 12 is DirectX 11 with Mantle Integrated

Mantle API vs DirectX 11 on Battlefield 4 – goldfries

Can I have DirectX 11 and DirectX 12 installed at the same time

NVIDIA Talks DX12, DX11 Efficiency Improvements - PC Perspective

AMD helps Firaxis create a truly exceptional DirectX 12 renderer