Hi basically i have a sngular stick of 8gb corsair vengeance 3000mghz ram, bought before i changed last minute to this motherboard due to costs. It only runs it at 2133, but i have since overclocked it to 2667 stable. However im looking to upgrade to 16gb in total i was wondering due to the mobo cap on stock speeds could i purchase a cheaper stick of8gb vengeance ram at a lower speed (2133/2666), then overclock them both to same speed to achieve dual channel and correct ram timings?? many thanks