Hi, It stands for chipset. Some of the pci-e lanes are run by the CPU and some are on the system board.
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 15  SLOT2 PCIE-G2-X1(CPH)  PCIe card connector 26  SLOT3 PCIE-G3-X16(CPU1)  PCIe card connector 37  SLOT4 PCIE-G3-X4(CPU1)  PCIe card connector 48  SLOT6 PCIE-G3-X4(CPU1)  PCIe card connector 6
PowerEdge T320