PCIe Riser Location and Differences
The PCIe riser that installs in PCIe slots 3 and 4 is different than the risers in PCIe slots 1 and 2. The riser for slots 3 and 4 supports two cards: a standard PCIe card and the internal HBA card. Do not attempt to install the PCIe riser for PCIe slots 3 and 4 in slots 1 or 2, and vice versa.
Figure 9 PCIe Riser Locations
Figure Legend
1 PCIe riser and installed PCIe InfiniBand card (slot 1)
2 PCIe riser and installed PCIe HBA card (slot 2)
3 PCIe riser and installed cluster interface card (slot 3) and the internal HBA card (slot 4) of this riser. Note: This riser is different from the risers in slots 1 and 2.