The reference DirectX 12 API (Feature Level 11_0) has performance targeted features while the other two level deliver graphical improvement and this is what really matters in improving the games visually. The feature level 12_0 comes with Tiled Resources, Typed UAV Access and Bindless Textures support. Feature Level 12_1 has the Raster Order Views.
AMD has recently confirmed that their current cards can support Feature Level 12_0 at best while NVIDIA’s Maxwell 2.0 architecture has support for Feature Level 12_1. The cards that feature level 12_ 0 support include Radeon HD 7790, Radeon R7 260 (X), Radeon R9 285, Radeon R9 290 (X) and R9 295X2. The older cards such as the ones based on Tahiti, Pitcairn that include all the 7000 series cards (excluding HD 7790), Radeon R9 270 (X) and Radeon R9 280 (X) feature up to Feature Level 11_1 support. Robert Hallock believes that there’s no problem with not feature DirectX Feature Level 12_1 support since features are performance enhancing tools are already available in 11_1 and 12_0 and most games won’t rely on utilization of 12_1.
According to Hallock, the absence of the feature level 12_1 is no problem in principle. So the key for games features are all included in the feature level 11_1 and 12_0. In addition, most games would already geared to the console and thus hardly rely on 12_1.
This however could hurt AMD in the long run against Maxwell (GeForce 900 series) cards that are compliant with DirectX 12 feature level 12_1 and that was proved in their recent GeForce GTX 980 Ti launch. NVIDIA’s older cards, such as Kepler and Fermi come with Feature Level 11_0 support with partial Feature Level 11_1 support.
