Firstly AMD 5800k is considerably costlier than i3 and I have seen in many benchmarks 6670 is outperformed by 7750 by more than 30% and 7750 can't be crossfired with 5xxx APU only 6xxx series GPUs can be.And if we are not using APU's integrated GPU then what's the point of buying an APU.. and can you tell me fire strike scores of fx 6100,4100 and 4130..??Also take a look at this 7750:1600 and 6670 around 1000 and after crossfire close to 1100
You've been given advice in multiple threads on this subject matter, and have been given advice one what components to buy, especially, and most specifically on processors.
If somebody tells you a good processor to use, after seeing the budget you're on,
do not then complain about the cost of a component, unless your budget is a useless number to go by.
By itself, the 5800k is a quad core with half decent entry level gaming performance. What people seem to forget is, you could get decent processing performance in games with a 5800k and a god damn Titan. Only games that are CPU intensive (RTS games mostly, like Starcraft II and Civ V) will require a more powerful core performance CPU.
An A8 with a 7970 can get almost identical performance in a GPU intensive game to a 3960x with a 7970.
Source :
http://www.anandtech.com/show/6934/choosing-a-gaming-cpu-single-multigpu-at-1440p/9