Model Configurations; Redundant I/O Interconnect For Pcie I/O Drawer - IBM z13s Technical Manual

PCIe I/O connection
The PCIe I/O drawer supports up to 32 PCIe features. They are organized in four hardware
domains per drawer, as shown in Figure 2-26.
Figure 2-26 Redundant I/O interconnect for PCIe I/O drawer
Each domain is driven through a PCIe switch card. The two PCIe switch cards provide a
backup path for each other through the passive connection in the PCIe I/O drawer backplane.
During a PCIe fanout or cable failure, all 16 PCIe features in the two domains can be driven
through a single PCIe switch card.
To support redundant I/O interconnect (RII) between front to back domain pairs 0,1 and 2,3,
the two interconnects to each pair must be driven from two different PCIe fanouts. Normally,
each PCIe interconnect in a pair supports the eight features in its domain. In backup
operation mode, one PCIe interconnect supports all 16 features in the domain pair.
Note: The PCIe Gen3 Interconnect adapter must be installed in the PCIe Drawer to
maintain the interconnect across I/O domains. If the PCIe Gen3 Interconnect adapter is
removed, then the I/O cards in that domain (up to eight) become unavailable.

2.7 Model configurations

When a z13s order is configured, PUs are characterized according to their intended usage.
They can be ordered as any of the following items:
CP: The processor is purchased and activated. CP supports the z/OS, z/VSE, z/VM,
z/TPF, and Linux on z Systems operating systems. It can also run Coupling Facility Control
Code and IBM zAware code.
redundant I/O
interconnect
Chapter 2. Central processor complex hardware components
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