1. For all you fails, the BF4 test that the author is doing, in this article, is a "beta." Meaning that it doesn't have the whole "sha-bang." You're basically playing a revised version of BF3 without all the additional goodies. That's why, pretty much all the FPS numbers for each resolution, is about the same results as if you were playing BF3. I know for sure AMD Mantle was never added to the Beta. It will be a AMD Driver thing. Doesn't look like DX11.1 was added either.
2. Between GTX Titan and 780, there should be a 13.2% difference in performance, roughly. If you do the math between both graphic cards' FPS performance, you'd see that the GTX Titan "does not" meet or exceed that 13.2% line. It fall flat from it. Averaging around 11.0%. So as a result, some would argue that this is a CPU Bottleneck... Do you get my point yet? What other way, what better way is there to determine if there is actually a CPU Bottleneck with the BF4 Beta. With Dual GPUs, the 2nd GPU isn't always pushing 100% because of scaling.
When BF3 first came out, and the NVidia was only starting to push Fermi (GTX 400 Series), there was some bottlenecking in the CPU when the game was loading up, but not during game-play up time.