Previewing AMD's Brazos: More Details on Zacate/Ontario and Fusion
 

The Zacate/Ontario APUs have an integrated PCIe interface sporting 8 lanes. Four of those lanes are used for AMD’s Universal Media Interface (UMI) - a bus that links the APU to the Hudson FCH. The remaining four can be used for discrete graphics or a combination of discrete graphics and other PCIe controllers. Both PCIe interfaces can run at gen 1 or gen 2 transfer rates.

http://www.anandtech.com/show/4003/p...rio-and-fusion