i5 or i7? If you got an i7 4770 then you should leave it alone.There is no gain(currently)from others cpus.I would suggest you to wait till summer in order intel to present their new architecture cpus.If you still want to upgrade, go for the i7 5930k or i7 5960x or if your budget is limited for the i7 5820k.But you will need a x99 motherboard and ddr4 ram