Foxconn ELA @ X-Bit Labs

"We know situations when manufacturers lay out the third graphics card slot, but it is usually running at what’s left. Since the chipset North Bridge has no extra PCI Express 2.0 lanes, the third slot uses the potential of the chipset South Bridge. So the third graphics card slot automatically loses support of the second generation PCI Express and can use 4 lanes maximum, i.e. it can work at PCI Express x4 speed at best."