The primary I/O bus for the main board is PCIe Gen3.
The following table lists the characteristics of the PCI-E bus segments.
Details about each bus segment follow the table.
NOTE: The signaling bit rate of PCI Express is 8.0 Gbit/s one direction per lane for Gen 3.
1. Indicates the number of physical electrical lanes running to a PCIe® connector.
2. CPU 2 indicates that a second CPU is required to access that specific PCIe® slot.
3. If only one CPU is used: It is not possible to use more than the top two slots on a 3-slot riser card or the top slot on a 2-slot riser card (in riser slot 1). Riser slot 2 and Riser slot 3 cannot be used.