avenseth12 :
The only way to do that and play those settings without problems is to replace your CPU with an Intel based cpu like the i5 4690k. That AMD fx6300 is a really poor gaming cpu. Here is a comparison of frames per second: You can see the Intel i5 gets about 30 fps more without problems.
http://www.overclock.net/t/1408955/fx-8350-vs-i5-4670k-in-terms-of-gaming/10
Don't listen to what this guy said. I tested so many cards with different CPU like FX-6300 stock / FX-6300 oc 4,6Ghz / i5 3570K stock / i5 3570K @ 4,4Ghz ... with 7850/7870/6970/580/670/680/280X/......... in BF3 and other games, no BF4 but since the CPU is demanding the same power with the same graphics card in BF3 and BF4 I can tell you exactly how it works. Of cours if you want the same frames in BF3 as in BF4 then it differs from CPU-usage logiclly cause you need then bigger card. So r9 280 max in BF3 = av 90 fps and in BF4 = 60fps so lower fps = less CPU-usage. And maybe even BF3 ask more cpu-usage, then you will be even more save with your setup in BF4 than my tested BF3 benches
You'r FX 6300 must be perfectly fine if you OC it at least above 4,2/4,3 Ghz. The FX-6300 at stock will retain you from some FPS, but not really bottlenecking and no lag for sure. If not so smooth for you, than OC it like I said.
I did mine with a low-end 49euro motherboard to 4,6Ghz very stable with max temps of 48 on the cores (recommended to stay under 70 degrees in full stress). I was able to go untill 4,8Ghz with this MB but it fluctueted with voltage and speed, cause my MB only has 4-pin cpu power connection, but you have 8 so no problem.
I just did a test yesterday in BF3 online 40 players with my FX-6300 (4,6Ghz) and i5 3570K (4,4Ghz) both with the same 7870 oc at 1920x1080 in ultra settings but no AA. And I was surprised that my AV. was exactly the same during 4 minutes benchmark. Even the FX did a little more frames. And then I looked up the CPU-usage. And I saw that on the FX he uses coplettely balanced the 5 cores + the 6th core going up and down (20-50%) and the average on all 6 core was like 55-60% usage. In the other hand the i5-3570K did use all 4 cores around 60-80% so around 65-70% of av. total usage. In other words my crossfireX 7870's gives some bottleneck to the i5 @ 4,4Ghz yes I tested it, but I didn't tested it on FX-6300 @4,6Ghz, but I'm pretty sure it will almost not bottleneck the FX at this speed. and 2x7870 is more performance than a R9 280 (like 20-30% in BF4 games) /, so you will be more fine with your 280 than my 2x7870oc.
The guy above showed you a graph. that tells nothing about your needs. Cause you asked for Ultra details in 1080p, not medium or low settings in 720p ! like in the graph.
How more FPS asked from GPU (so bigger GPU or lowering the settings/resolution) how more CPU will work to maintain the 100% the asked GPU frames/s, because a GPU always try to give his full potential frames (so 100% work-load)
And yes a i5 is better for games that just need good 2-3 cores in games like Crysis / far cry / COD's .....
But what the hell, BF3 that is 3 years old uses nicely the six-cores all together if I put resolution 1680x1050 and High settings in 30-64 players maps. So 6 core processor is the sweet spot for BF3/4 MuTIPLAYER!
But I still love more my i5 3570K
but i5 3570K @4,4Ghz + MB has a price tag of 380euro (1 year ago) and my FX-6300 @ 4,6Ghz + MB costed 150euro (5 moths ago) so 130 euro cheaper.
I hope I helped you a bit. Let me know if you want to know more