Turns out Sony is using a modified and improved version of DirectX 11 that will improve shader pipeline access, among other things.
Those improvements include better shader pipeline access, improved debugging support features out the box, and much lower level access to the system hardware enabling developers to do more cool things. Thats achieved not only through an modified DirectX 11.1 API, but also a secondary low-level API specifically for the PS4 hardware.
12 CUs (768 ALUs)
1.84 TFLOPS (+40%)
57.6 GTex/s (+40%) - Texture Fill Rate
25.6 GPix/s (+90%) - Pixel Fill Rate
18 CUs (1152 ALUs) - Compute Units