I'm pretty underwhelmed by the Wedge switch in this chassis though. Half of the ports (16 of them!) are left off, meaning that it's only really useful if you have fewer than 15 compute nodes and don't want to have a full-bandwidth uplink anywhere.
The only way this design makes sense is if the 16 ports out the back of the switch are connected to a larger bus. That's how it's used in the 6-pack chassis, and how the "line card" connects to the rest of the 6-pack fabric. The other place it may make sense is if there's some sort of network bus on the OCP racks, with fiber transcievers on the top of rack or something.