The server supports the PCIe 16-lane format. PCIe card slots connect to root complexes in CMPs that are mounted on CMIOUs. For more information about PCIe device root complexes, refer to the SPARC M8 and SPARC M7 Servers Administration Guide.
Each CMIOU has three slots, each of which can hold a single PCIe x16 card carrier. The slot numbers repeat from 1 to 3 in each CMIOU, so to identify the physical location of a card you must specify the CMIOU number, as well as the card slot number. Note that the physical numbering for card slots starts at 1 (not 0) and ends at 3 (not 2).