A Demonstration of PCI Express Generation 3 over a Fiber Optical Link

In 2007, the PCI SIG released an external cabling specification enabling interconnection of PCI Express systems at 2.5 Gb/s (Generation 1) and 5Gb/s (Generation 2), facilitating access to PCIe extension and expansion. Copper cabling solutions appeared in the market in a variety in channel widths to provide connectivity, but were limited in link distance and became bulky in size & weight at higher channel counts. These copper cabling solutions were able to meet the basic needs of emerging external expansion applications for Gen1 and Gen2.
With the recent adoption of PCIe's Gen3 specification, copper interconnects are finding it increasingly difficult to keep up with price, performance and size/weight needs for 8Gb/s interconnects.
Fiber Optic technology provides an alternate solution to high channel count PCIe Gen3 interconnects, with a value proposition of increased link distances, lower size/weight, higher performance and competitive pricing.
PLX Technology, an industry leader in PCIe IC solutions, and Avago Technologies, the industry leader in parallel fiber optic products, recently collaborated on a demonstration showing the first PCI Express Gen3 end-to-end fiber optic link, delivering a full 64Gbps (128Gbps bidirectional) performance for PCIe applications. This application note describes the components used, the demonstration configuration and a basic overview of functionality of fiber optic links.