With dx12 gaming around the corner been looking at a rig comes with i7 6700k and 16gb 1600mhz ram and 4gb gtx 970 costing around & £1300 my rig is i5 3570k stock gtx 960 and 16gb 1600mhz ram also if I upgraded to a gtx 970 would there be much diffrence in performance between both rigs