Re: Thinking about a new build
the performance difference between the devil's canyon i7 (4790k) and the 6700k, at stock clocks, heralded about a 9-10% overall boost in performance, and a minor improvement in instructions-per-clock. This information was current as of the 6700k being released - however board manufacturers have since had a rethink with BIOS coding due to a problem they discovered; so it could be different now.
In my opinion, the 4770k is still just as relevant in the performance CPU market as it was before skylake, especially if you're using it to game. Unless you yearn to be running whatever the latest thing is, you'll be fine with that 4770k for some time yet.
If you're looking for a performance boost, is that 4770k overclocked?
EVGA SLI Micro Z68 // Intel i5-2500k // 8GB Corsair Vengeance 1866MHz // Overclocked 2GB MSI R9 270X // Corsair Carbide SPEC-03 // Kingston Hyper-X 120GB // 2TB WD Green + 500GB WD Black