Does anyone know what "CPH" stand for?
It's listed in the System Board Connectors section of the PowerEdge T320 user manual (excerpt below).
4 SLOT1 PCIE-G2-X4(CPH) PCIe card connector 1
5 SLOT2 PCIE-G2-X1(CPH) PCIe card connector 2
6 SLOT3 PCIE-G3-X16(CPU1) PCIe card connector 3
7 SLOT4 PCIE-G3-X4(CPU1) PCIe card connector 4
8 SLOT6 PCIE-G3-X4(CPU1) PCIe card connector 6