Fortnite is about to make better use of your fast gaming rig. Epic is rolling out an update to the Windows version of its battle royale shooter that adds support for DirectX 12. If you have a high-end graphics chipset, you should see "higher and steadier" frame rates thanks to both better CPU peformance and better distribution of 3D rendering tasks across multiple cores. Accordingly, AMD has posted new drivers that enable DirectX 12 support in Fortnite.
To some extent, this is about laying groundwork for bigger and better. Epic plans to add DX12-specific features in the long run, and this gives it an opportunity to "shake out any bugs" by seeing how the technology works in the game as it is today. You're serving as a tester, then, but that test might pay off if Fortnite makes better use of your hardware.