Microsoft revealed DirectX 12 at the annual Game Developers Conference (GDC) in San Francisco. it's lighter and more efficient API that allows developers to control hardware resources more directly. Microsoft demonstrated the new API with a tech demo of the Xbox One racing game Forza running on a PC powered by an NVIDIA GeForce Titan Black. Microsoft says that PC, smartphones, and Xbox One will see boosts in performance when the new tools arrive but the company haven't announced whether DX12 would support Windows 7 or not.
First DirectX 12 games will arrive in holiday 2015.