looks like a nice board, i have looked up this mobo on newegg and it doesn't epecify how many lanyes each pcie slot has
you want to get a mobo that supports 16 lanes on a single pcie or 8x 8x on both, some crap mobos will have 16x 4x
I would suggest this http://www.newegg.com/Product/Product.aspx?Item=N82E16813157271
PCI Express 3.0 x16
2 x PCI Express 3.0 x16 slots (PCIE2/PCIE4: single at x16 (PCIE2) / x8 (PCIE4), or dual at x8 (PCIE2) / x8 (PCIE4)) (PCI Express 3.0 with Intel Ivy Bridge CPU, PCI Express 2.0 with Intel Sandy Bridge CPU)"