July 1, 2020 Ever since people figured out that the Raspberry Pi 4 has a PCIe bus, the race was on to be the first to connect a regular PCIe expansion card to a Raspberry Pi 4 SBC.

Those have a length that’s defined by the width of the bus. In the case of PCIe, there is no bus, so instead we get the ‘core’ connector pin-out with a single lane (x1 connector).