Hello sorry for my english need help: i have LGA 1150 i5-4670 NON K 12gb 1600Mhz DDR3 gtx 970 g1 gameing 1080p freesync 120hrz 27 inch monitor , my birthday come close and i want to make one upgrade and im between GPU: rx590 since freesync monitor or gtx1660 or try find CPU: i7-4790k (worth it?) becouse of "bottleneck" 300euros ish budget... Campaing (single player) mostly player, or sould i look for rig upgrade without gpu first? thank you in advance