Subsystem Positioning And Cabling - IBM pSeries 7311 D10 Service Manual

Subsystem Positioning and Cabling

I/O subsystems can be installed in a standard 19-inch EIA rack in any location. The cables that connect
the subsystems allow some flexibility in drawer placement, but the I/O subsystems should be located
above the processor subsystem to which they are connected in the same rack.
Up to eight I/O subsystems can be connected to a processor subsystem. Use the following guidelines:
v Each I/O subsystem connects to the processor subsystem using one system power control network
(SPCN) cable loop.
v Each I/O subsystem connects to the processor subsystem using one or more remote I/O (RIO) cable
loops.
v Lowest cost configurations allow up to four I/O subsystems connected to the processor subsystem using
a single RIO loop.
v Optimum performance is achieved when each I/O drawer is connected to the processor subsystem
through its own RIO loop.
Note: The cabling illustrations in this section show examples of how the cabling between a processor
subsystem and connected I/O subsystems can be done. The example illustrations show the logical
connections of SPCN and RIO cables. Your system's cables might be physically connected in a
different way from these examples.
SPCN Cabling
I/O subsystem SPCN cables are connected to the processor subsystem unit in a loop configuration. The
SPCN cables are connected in a loop so that the system has two paths to each I/O subsystem. Up to
eight I/O subsystems are supported on one SPCN loop.
One I/O Subsystem, Two I/O Subsystems: The illustrations on the left show one I/O subsystem
connected to the processor subsystem. The illustrations on the right show two I/O subsystems connected
to the processor subsystem using one SPCN loop.
Processor Subsystem Connected to One or Two Model D10 I/O Subsystems:
6 Eserver pSeries 7311 Model D10 and Model D20 Service Guide
1 Processor Subsystem
2 I/O Subsystem