Quote from Dart:
As I suspected, Asus doesn't make a 6 or 7 pci-e X16 board. You have to go intel for that many slots. I guess in the money saving AMD market there isn't anyone willing to spend $500 for a motherboard.
you can have all the 16x slots you want, but you won't find a motherboard that doesn't down clock them to 8x or 4x. intels best single socket cpu has 40 pcie lanes, you could call it 40x. the motherboard manual will detail this
here is my fancy all 16x slot intel board. when populated, it equals 40x
Slot No.
Slot Description
1
PCIe 2.0 x16_1 slot (single at x16 or dual at x8/x8 mode)
2
PCIe 2.0 x16_2 slot (x8 mode)
3
PCIe 2.0 x16_3 slot (x4 mode)
4
PCIe 2.0 x16_4 slot (single at x16 or dual at x8/x8 mode)
5
PCIe 2.0 x16_5 slot (x4 mode)
6
PCIe 2.0 x16_6 slot (x8 mode)