PCI-SIG completes external PCIe specification

The PCI Special Interest Group has completed version 1.0 of the specification for external PCI Express connectivity. As its name suggests, the PCI Express External Cabling 1.0 spec enables systems to connect up to external devices via PCIe. It allows between one and 16 lanes of connectivity for a maximum 8GB/s of bi-directional bandwidth (4GB/s in each direction), just like current internal PCIe implementations. Interestingly, PCI-SIG says the PCIe External Cabling spec gives guidelines for a “practical” cable length but doesn’t actually specify a maximum cable length. Nevertheless, PCI-SIG president Al Yanes says external PCIe can be used for I/O expansion drawers, external graphics processors, communications equipment, and more. Just as PCI-SIG released a new internal PCIe specification with support for doubled signaling rates last month, the group expects to double transfer speeds in a future version of the external spec.