Its not a matter of a cpu bottlenecking a graphics card. Its what your doing with the system that determines which is going to be utilized the most and first. If your doing something completely cpu demanding, then a 780ti will do nothing more than a 750, if your gaming single monitor style, then 780ti will give you what ultra at like 100fps, and the 770 gives ultra at 60? Both totally playable and not worth $800. But if your gaming, but running tri monitors, that's more taxing on a cpu and gpu than traditional single monitors. And the 8120 will/should be able to push tri monitors, if you jumped up to 4770k you will notice a great boost in performance.
There are several reviews showing 8350 vs i5 vs i7 running multi monitors and 4k res. Using the same graphics card, the 8350 is always below the pack, with i7 at extreme configs well well above the amd.
Not dissing amd, nor trying to say intel is better. Im just saying what each is better at than the other.
Example, I render using programs that utilize full core potential, so all 8 cores. i5 is well below mine, i7 is neck and neck. But if I were to use a different program or game or anything which restricts full core potential, then botht he i5 and i7 will smoke mine.