AMD Radeon HD 5870 PCI-Express Scaling

Thanks to the modular, scalable design of PCI-Express, consisting of independent data-paths called ‘lanes’, motherboard designers can control a limited PCI-Express lane budget, and offer multiple PCI-Express x16 slots. In mid-range motherboards, and particularly in most motherboards based on Intel’s newest P55 chipset, 16 PCI-Express lanes are used to drive two PCI-Express slots with bandwidths of 8 lanes each.