videocard new help afraid bottleneck g3250

Hello guys, 1st of all sorry for my bad English. So i want to buy a new GPU, but I dont know which. But I'm afraid for the bottleneck. My system is Intel Pentium G3250 3.20GHz, 6GB RAM DDR3, 1TB Memory. So now I am with GT 610, but I want new. I used this site http://thebottlenecker.com/ and it...