Mapping PCIe Expansion Slots
The enclosure has two PCIe switches integrated on the system board which map the Shared PERC storage slots and PCIe expansion slots to the PCIe mezzanine cards on the server modules.
NOTE: Before mapping or unmapping a PCIe device, the server module must be turned off.

NOTE: The PCIe switch mapping is controlled by the firmware and depends on the software license installed on the system:For more information on PCIe slot configuration licensing, see the Dell Chassis Management Controller for Dell PowerEdge VRTX User’s Guide at dell.com/esmmanuals.

The switches map the mezzanine cards to the PCIe slots on the enclosure's system board. There are five PCIe low profile slots on the system board and three full-height, full-length PCIe slots on the PCIe riser. All the PCIe slots can be mapped to the PCIe mezzanine cards on the server modules to provide I/O expansion for the system:

PCIe mezzanine Fabric B and Fabric C cards on each server module are mapped to the PCIe switches which further map to the PCIe slots and the Shared PERC slots on the enclosure's system board.
NOTE: For information on the specifications of the supported PCIe cards, see Technical Specifications.

Figure. Mapping PCIe Expansion Slots — Half-Height Server Modules
The figure
shows mapping PCIe expansion slots (half-height server modules).
Figure. Mapping PCIe Expansion Slots — Full-Height Server Modules
The figure
shows mapping PCIe expansion slots (full-height server modules).