During the Windows 10 Keynote Xbox Division Head Phil Spencer introduced a video comparison showcasing the performance of the upcoming DirectX 12 API pitched against the current DirectX 11.
You can see a recording of the video below, and it showcases a scene that gets more and more complex. On DirectX 11 framerate drops until it reaches zero, while on DirectX 12 the same hardware keeps going and adding more complexity.
According to Spencer, DirectX 12 will give developers a finer control of the CPU and the GPU, and on CPU-bound games on PC it will provide up to 50% performance increase, allowing developers to create “amazing scenes on screens.”
On top of that, DirectX 12 will also focus on battery life for mobile devices, cutting power consumption in half, allowing gamers to play longer on their smartphones and tablets.
Spencer also mentioned that Unreal Engine 4 and Unity already support DirectX 12, and hunreds of developers are already working with it.