You can install a maximum of six PCIe cards into the server in slots 1 through 6. See Rear Panel Components (Service) and Component Locations (Motherboard, Memory, and PCIe Cards).
Additionally, there is an internal HBA PCIe card with SAS3 12 Gbit/sec capability. This internal HBA PCIe is located in slot 7 (next to slot 5). There is no external slot or access for this card. See Servicing the Internal HBA PCIe Card.
Follow these guidelines when configuring PCIe cards:
The Sun Storage 12 Gb SAS PCIe HBA internal card must be installed in slot 7. This is a configuration requirement.
Any empty PCIe slot must be populated with a PCIe filler. Use only the PCIe fillers provided with the server, to maintain proper airflow and EMI conformance for empty slots.