This may indeed be old news but I have recently sent off some Corsair 1866MHz 2x8GB modules off for RMA and they want to replace it with 1600MHz stuff. Unfortunately for me upgrading to DDR4 means new board, means new CPU. I would like to avoid that if possible but still retain my origin spec RAM speed. A quick online shop check seems most places do not stock anything above 1600MHz any more. I guess the DDR3 ship has left for good?