It’s not clear why Microsoft lists Kepler as supporting DirectX 11_1 while Nvidia shows it as limited to DirectX 11_0 below, but either way, the point is made: DirectX 12 support is nuanced and varies between various card families from every manufacturer. AMD’s GCN 1.0 chips include Cape Verde, Pitcairn, Oland, and Tahiti and support feature level 11_1, whereas Bonaire, Hawaii, Tonga, and Fiji will all support feature level 12_0. Nvidia’s various 4xx, 5xx, 6xx, and 7xx families will all support DirectX 12 at the 11_0 or 11_1 feature level, with the GTX 750 Ti offering FL 12_0 support.
The issue has been further confused by claims that Maxwell is the only GPU on the market to support “full” DirectX 12. While it’s true that Maxwell is the only GPU that supports DirectX 12_1, AMD is the only company offering full
Tier 3 resource binding and asynchronous shaders for simultaneous graphics and compute. That doesn’t mean AMD or Nvidia is lying — it means that certain features and capabilities of various cards are imperfectly captured by feature levels and that calling one GPU or another “full” DX12 misses this distinction. Intel, for example, offers ROV at the 11_1 feature level — something neither AMD nor Nvidia can match.
If you own a GCN 1.0, Fermi, or Kepler card, you’re going to get the DirectX 12 features that matter most. That’s why Microsoft created feature levels that older GPUs could use — if Fermi, Kepler, and older GCN 1.0 cards couldn’t benefit from the core advantages of DirectX 12, Microsoft wouldn’t have qualified them to use it in the first place. The API was purposefully designed to allow for backwards compatibility in order to ensure developers would be willing to target it.