This is so smart motherboard layout with x1 and x4 PCI-E.
Smartest motherboard layout I ever saw.
This board have space for one nice Sound Card in x1 slot, one nice Intel 750 SSD, and one nice Samsung 950 PRO and
graphic cards. Or Intel 750 SSD could be installed in x8 slot and Thunderbolt in x4.
I don't know why companies make boards without small PCI-E slots or they build 3x PCI-E x1, for what three x1 slots?
Every high end motherboard in future and special motherboards now when chipset is better and better need to arrive with x4 PCI-E slot or even better x4 and x1.
Because small devices as PCI-E SSD, USB 3.1 Port cards, Thunderbolt II,... can't occupy big ports and influence on GPU speed.