So I read through this as I am interested in possibly using crossfire. My mobo supports 1x16, 2x8, 1x8x2x4. I was hoping that the OP might have some specs of these against each other. I did not read through all 28 pages, but is there an updated place that we can see the 1x16 vs. 1x16x8 vs. 1x16x4 vs. 2x8 vs. 1x8x4 vs. 2x4? If not I'd be glad to do some more digging, but perhaps OP could be updated to 2014/2015 mobo and specs?