PCI slot priorities for the 5803 and 5873 expansion units

System description

The 5803 and 5873 expansion units are 24-inch, rack-mountable, I/O expansion drawers that are attached to the system by using 12X double data rate (DDR) cables.

The expansion units can accommodate 20 PCIe, generation-3 cassettes. These cassettes can be installed and removed without removing the drawer from the rack. The expansion units do not support I/O processor (IOP) adapters.

Figure 1 shows the rear view of the expansion unit.

Figure 1. Rear view

Table 1 describes the location codes that are shown in Figure 1.

Slot priority

If the expansion unit is connected to a 9119-FHB system, place the adapters in the slots with the following slot priorities:

2 planar loop

1 planar loop, planar 1

1 planar loop, planar 2

I/O chip descriptions

The expansion drawer has two I/O planar boards, and each planar has three I/O chips. Each I/O chip controls three or four PCI host bridges (PHBs) and each PCIe slot connects directly to a PHB.

Slots P1-C1 through P1-C6 and slots P2-C1 through P2-C6 provide the best performance. Place the highest performance adapters in these slots in the slot priority order listed in previous priority lists.

Slot maximums for supported adapters

Table 2 shows the maximum number of supported adapters allowed for connectivity by feature code (FC). However, for optimum performance, you might want to further limit the total number of high bandwidth and extra-high bandwidth adapters. Performance notes follow the table.

Performance notes

Use the information in this section to help determine the maximum number of adapters that can be placed in a system while still maintaining optimum performance.

Table 2 shows the maximum number of adapters allowed for connectivity. However, for optimum performance, you might want to further limit the total number of high bandwidth and extra-high bandwidth adapters. Use the following guidelines for connecting the adapters:

• Attach no more than three Gb Ethernet ports per PHB.
• Attach no more than three high-bandwidth adapters per PHB.
• Attach no more than one extra-high bandwidth adapter per PHB.
• Attach no more than one 10 Gb Ethernet port per two processors in a system. If one 10 Gb Ethernet port is present per two processors, no other 10 Gb or 1 Gb ports are allowed for optimum performance.
• Attach no more than two 1 Gb Ethernet ports per one processor in a system. More Ethernet adapters can be added for connectivity.
• For best performance, connect each 5803 and 5873 half-drawer (10 slots) to a feature 1816, 12X DDR InfiniBand I/O hub controller, in the 9119-FHB system.