Host cable adapter, target cable adapter, two-slot backplane and PCIe x4 cable. The host adapter card inserts into any PCI Express x16 slot on the host motherboard. The high speed cable allows data transfers to and from the host at 20Gb/s. The target cable adapter fits into the endpoint slot on the two slot backplane seamlessly connecting a downstream I/O device to the host computer without software. The two slot backplane can be installed into any downstream chassis or used for testing purposes.