FX 8320 or FX 8350

What's the main difference between these two? Is it for overclocking or is there a significant difference between them in gaming and productivity.

Clock speed, and binning. Everything else is the same - 4 Piledriver modules, same caches, same TDP, etc. If you plan to overclock, these two should be very similar, if not identical. Otherwise, the FX-8350 will be noticeably faster due to its higher stock clock frequency.

every am3+ motherboard supports overclocking

just change the multiplier from 17.5 to 20, leave the voltage alone and you basically have a 8350

But will I see a difference in gamin or when I'm using a 3D modeling program. 


There is a difference, and it is worth paying.

At the same clock speed - no. An 8320 @ 4.0GHz (4.2 Turbo) will have identical performance to a stock 8350.


yes using both at stock, no when both are at same clock

also don't use either, intel is pretty much the way to go for edit/render/modeling

well as long as you're good at making builds on a tight budget like me, you can fit intel in