The difference between AMD and intel for gaming.
Firstly, you need to decide what your priorities are, and what you will use the PC for.
Things such as: light gaming, heavy gaming, basic work (e.g. MS Office), heavy work (e.g. video editing, 3d modeling).
For the most part in current games the biggest difference will be made by the selection of the GPU. Get a great GPU + worse CPU rather than worse GPU + great CPU.
The AMD FX CPU's have many cores, which are weaker.
intel i5's have less cores, which are stronger.
The intel's consequently have better performance per core. In older games, the intels perform much better as those games are optimised for good performance with only a few cores (single-threading).
In newer games, the AMD FX's really shine due to the introduction of games using more cores (multi-threading).
Hope you can understand if you have budget for gaming pc over then 500 dollars you can go with Intel and buy a good gpu .. as i mentioned above you have can get a Amd processor but good GPU ..