That's like the saying the best 3 cylinder compact car that can tow 10,000 lbs
The BEST FM2+ chip around is the 880k and that is not even at i3 level performance.
This will bottleneck a 960 or 470 on anything CPU intensive.
In regards to a 390, outside of the select few titles that use the GPU hard but barley need anything from CPU, for any other game you could literally buy a cheaper card and not see any gameplay difference.