DIY PCIe Over Fiber: Off‑The‑Shelf SFPs Ignite a New USB/PCIe Link

Hackaday covers Sylvain Munaut’s experiment to run plain PCIe over fiber using inexpensive QSFP transceivers, a Raspberry Pi 5, and custom SFP PCBs to switch between PCIe edge and USB 3.0 connectors. The setup demonstrates a Gen 2 x1 PCIe link over single‑mode fiber, building on Eli Billauer’s 2016 groundwork for Gen 2 over SFP+. Compatibility hurdles—device detection, side‑channel clocking, and Gen 3 equalization training—pose challenges for higher generations. The project aims to scale to Gen 3–5 (potentially x4 to x16) in future videos, with the hope of external GPUs operating at near‑full bandwidth without Thunderbolt.