IBM Power 595, Technical Overview And Introduction, Page: 95 / 188

Chapter 2. Architectural and technical overview
83
2.8.1 Connection technology
RIO-2 and 12x connectivity is provided using GX bus adapter based, remote I/O hubs. These
remote I/O hubs are listed in Table 2-19.
Table 2-19 Remote I/O hubs
Each I/O hub provides two ports that are used to connect internal 24-inch I/O drawers to the
CEC.
The RIO-2 I/O hubs are currently available and the 12x I/O hubs have a planned-availability
date of November 21, 2008.
I/O hub adapter plugging rules
The I/O hubs are evenly distributed across the installed processor books. The installation
order follows the processor book plugging sequence listed in table Table 2-1 on page 42 with
the following order of priority:
1. Bottom narrow slots are across all processor nodes.
2. Upper narrow slots are across all processor nodes.
3. Bottom wide slots are across all processor nodes.
4. Upper wide slots are across all processor nodes.
This information (bottom and upper notation) is applicable regardless of the orientation of the
processor books (upper or lower). For example, bottom means bottom whether you are
plugging into a processor book installed in an upper or lower location.
An example of the I/O hub installation sequence for a fully configured system with eight
processor books and 32 I/O hubs is shown in Figure 2-35 on page 84.
Feature Description Form
factor Attach to
drawer(s) Support
AIX IB
M i
Li
n
u
x
#1814 Remote I/O-2 (RIO-2) Loop Adapter, Two Port narrow 5791
9
—
9
#1816 GX Dual-Port 12x HCA narrow 5797, 5798
9 9 9
Important: When your Power 595 server is manufactured, the I/O hubs are evenly
distributed across the installed processor books. I/O connections will then be distributed
across these installed I/O hubs. If you add more I/O hubs during an upgrade, install them
so that the end result is an even balance across all new and existing processor books.
Therefore, the cabling relationship between the I/O hubs and drawers can vary with each
Power 595 server. We suggest that you document these connections to assist with system
layout and maintenance. I/O hubs cards can be hot-added. Concurrent re-balancing of I/O
hub cards is not supported.