DirectX 12 is the upcoming graphics API from Microsoft, and it is expected to change PC gaming forever. The API should be able to push more performance from old to new graphic cards, potentially enabling CGI quality graphics.
Brad Wardell, CEO of Stardock Studios, claimed on his blog that DirectX 12 will perform faster compared to DirectX 11. He said that DirectX 12 splits the load across multiple cores while DirectX 11 does everything on a single core. This should allow for better graphics performance for PC gamers and possibly gamers on the Xbox One.
Wardell highlighted an example on his blog, which proves the speed improvements that developers will get from DirectX 12. However, we should point out that each developer will have a different take on the API's performance. Wardell's claims are only his personal opinion and may not be shared by all video game developers.