If you do not have the same model and quantity your Dual Channel capability will not work properly
Third if you do not use matching ram (2 x 4gg and 2 x 4gb) but instead (2 x 4gb and 1 x 8gb) lots of motherboard will not work under that setup, your motherboard only takes memory in pairs of two, 1 stick (single channel memory), 2 sticks or 4 sticks, a 3 stick combination will not boot
As you caN see from your motherboard manual this is the only setup that will work.
One more thing in your manual they specify that 1600mhz memory will only work if you have an Intel 22nm (ivy bridge) CPU
Hope that helps
Edited by Alzeimer, 26 February 2013 - 08:07 AM.