FPS Test: DX11, DX11E and DX12 (Patch 29.1) - Reddit
DX12 takes some time to become smooth - at the very beginning it caches shaders in the form of files "D3DDriverByteCodeBlob.ushaderprecache" and "D3DGraphics.ushaderprecache" in the folder C:\Users\*username*\AppData\...