Well, back in 2014 at the time I wrote my response I was not aware of any rumors of a forthcoming AMD CPU. AMD's current Piledriver generation CPU came out back in December 2011 so when Zen comes it October 2016 that means will be almost 5 years later that AMD has finally come out with a new CPU architecture. They have been in some serious financial trouble and they still are. I just hope the new Zen CPU can revitalize the CPU side of the company because they need to be able to sell CPUs that can actually allow AMD to make a good profit margin and grow as a company rather than contract. AMD had to cut prices on Piledriver CPUs to razor thin margin to be able to compete against Intel. Razor thin profit margins is not a good thing since that is not enough money to support other products that are not making any money at all as well as money for continued research and development. They also lost a lot of ground to nVidia which now owns at least 80% of the dedicated GPU market.
Regarding the performance of AMD's CPU to Intel's CPUs in games, that depends on the specific games. Most games like GTA 5 are not very CPU dependent so the performance difference between competing AMD and Intel CPU will be relatively small. Below are benchmarks GTA 5 with the GTX 980 Ti and various CPUs. The Core i5-4440 is not part of the chart, but the older generation Core i5-3470 gets 78 FPS; the i5-4440 will probably get either 79 or 80 FPS. The FX-8350 comes in with 72 FPS which is not that much slower and on a monitor limited to 60Hz there will be no difference since the max FPS that can be displayed will 60 FPS. On a 120Hz / 144Hz monitor players will not notice much of a difference either. Nevertheless, the Intel i5-4440 does give better results if you focus on the benchmarks.
However, if you look at the next set of benchmarks, you will note that a Core i7-4770k that has been down clocked to 2.5GHz performs better (by 1 FPS) than a FX-3850 overclocked to 4.5GHz. When the FX-8350 is clocked down to 2.5GHz it only manages to get 47 FPS.
http://www.techspot.com/review/991-gta-5-pc-benchmarks/page6.html
However, if you play games that are more CPU dependent, then you will see a difference. Fallout 4 is an example of a time that is more CPU dependent than GTA 5, but it is not the most CPU dependent game out there. While the dual core i3-6100 manages to get an average of 88 FPS when paired up with a GTX 980 Ti, the FX-8350 only manages to get 67 FPS. The Core i3-6100 manages to provide 31.3% better performance. On a monitor that is limited to only 60Hz, the performance will look the same. But on a 120Hz / 144Hz monitor players should notice a difference. Again, the i5-4440 is not in the benchmark, but since it is clocked a little faster than the i5-3470, it should get about 100 FPS in Fallout 4 with the GTX 980 Ti.
http://www.techspot.com/review/1089-fallout-4-benchmarks/page5.html