Silicon Graphics 2400, Owner'S Manual

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Hardware Overview
5
The modules communicate using the high-speed (1600 MB/sec) CrayLink Interconnect
link. The CrayLink Interconnect (also known as the interconnection fabric) link consists
of a set of high-speed routing switches and cabling that enables multiple connections to
take place simultaneously. Using the CrayLink Interconnect, hardware resources
(including main memory) can be shared and accessed by other modules in the
configuration. For more information on the CrayLink Interconnect see “CrayLink
Interconnect” on page 11.
Note: Not all rack systems have two fully self-contained modules; some may have only
one; some configurations may have as many as 16 modules. For more information on the
different rack configurations, see Chapter 4, “System Configurations.”
Figure 1-5 provides an overall block diagram of an SGI 2400 server rack system. The
major hardware components include the:
• CPU and memory (Node) board
• Router board
• BaseIO board
• XIO slots
For a description of these components, see Chapter 2, “Chassis Tour.”
The rear module diagram shown in the top portion of Figure 1-5 appears in the back of
the chassis between the Node boards and fan tray. This diagram provides a map that tells
system installers where to install Node boards and XIO boards into the system. Use this
diagram to help correspond the Node boards and XIO blocks in the block diagram to
their actual physical location in the chassis. For more information on how to read this
diagram, see “Board Configuration and Layout” on page 20 in Chapter 2.
Figure 1-6 shows how some of the major hardware components connect inside a system
module. All these components interface using a common midplane with connections
made to both the front and the back.