When it comes to SLI, most single AMD64 CPU solutions will only have dual 8x lanes due to the limitations of the chipset, but with a dual Opteron system, motherboard manufacturers are able to provide users with dual 16x PCIe lanes. Let me repeat that again. Dual 16x PCIe lanes. Truth be told, even AGP solutions are hard pressed to satuarate the entire bus, but it is expected that as technology progresses, especially in the high-end workstation market, cards will come out that will be able to saturate a 16x bus.



Link: HCW