OCP add-in card usage is proliferating beyond compute platforms, into storage platforms. Though initial OCP mezzanine deployments have been for NICs, but new peripherals, such as SSDs, hardware accelerators are also being considered for PCIe interface. Further, advent of OCP 3.0 provides a unified interface connector to accommodate these multiple types of PCIe mezzanine peripherals.These multitude of mezzanine peripherals and OCP platforms poses challenges from electrical interoperability perspective. Much of current OCP designs leverage PCI-SIG CEM specifications as guideline for channel topology. OCP platform channel topology and form-factor differences limit the ability to assess PCIe electrical conformance at mezzanine connector for both the platform and mezzanine cards. To address these limitations, Facebook along with NIC and other platform developers is working to develop PCIe Conformance methodology for OCP platforms and mezzanine cards, similar to electrical testing defined by PCI-SIG for standard CEM Add-in cards.
