I know both are better than what I have
I'm really only looking at doing one or the other at the moment.
Budget is probably $400 simply because I'd need a new mobo if CPU is the better to go with. I usually go for the $200-250 range of GPU.
I guess I'm asking, if I get a 7850/70, is my E8400 a bottleneck for gaming? If so, I'll probably go for the CPU option.
If current CPU is fine, then I'll go for a better GPU.