Unless you have a specific program that is designed to efficiently make use of all 6/8 cores, an i3-4130 will outperform an fx-8320.
Cores and Clock speed don't really mean anything when comparing intel and AMD. But comparing intel vs intel or amd vs amd it helps.
Not many games or programs will make use of even 4 cores, so 6 and 8 are just wasted cores.
If you want AMD look to the A-series, as they're more like what intel's i-series (but still pretty inferior).
Intel is better, and you pay more for it yes, but you don't need an i7 to play games or browse the web, i3s have little to no issues playing games at their max settings, as long as your GPU is good enough.