A cpu for an FM2+ mini ITX build?

Hey guys, I want to ask you an advice for a new build. I really want to make up this build and I want to know which CPU is the most powerful, just talking about a the cpu cause I'm gonna use a r9 270 as a graphic card.

Should I get a 6800k, a 7700k or a 7850k??

Get either the 7700k or the 7850k...The 7850k is faster and 7700k has part of the iGPU disabled. It dpends on how much you want to spend. The 6800k is older and slower, on average

Why not get the Athlon 760k CPU if you are going to get a dedicated GPU?

I'm For whatever is gonna fit into an FM2+ socket, I just want to Know weach one has the better performance

Agreed

The 7850k is about 10% faster on average at stock, the Athlon though is a great value CPU, cheap and easily overclockable to 4.5GHz. Steamroller doesn't overclock that good, so that's a thing you want to consider especially if you're going to be using a dedicated GPU. On the other side, Steamroller is just more power efficient than Piledriver (Athlon 760K) and the 7850K's GPU is poweful enough for mild gaming and everyday tasks.

for mini itx i would personaly go with intel. like a i5-4570 with a H87 itx board. for example.

If you still want FM2+ then i would personaly grab the Athlon 760K.

thank you guys. I'll go with the athlon.