Not at all. BF4 is by far the most CPU hungry game I have ever played (Talking multi-player here, 64 man servers). Like I mentioned above, my CPU sits at 95% utilization (average, it hits 100% at times). Even a 4.5Ghz 2500K will sit at 80-90% CPU.
Thats why mantle has less of an effect on faster CPU's.
The question was primarily rhetorical but I stated it to show the BS AMD is trying to pull. (The CPU usage is irrelevant, I was asking about fps @ ultra).
FX 4300 @ 3.8 = 56 fps.
A10-7850k + DX = 38 fps, a10-7850k + mantle = 55 fps.
CPU wise FX 4300 ~ a10-7850k
Something doesn't look right.