Silicon Graphics Origin 3900 User Manual page 73

007-4653-001
The following configuration rules apply to the Origin 3900 servers:
• When the server contains more than four Cx-bricks, the server must be configured
with metarouters (also referred to as R-bricks). For example, servers that contain 6
or 8 Cx-bricks require two metarouters. The third column of Table 2-1 indicates the
number of required metarouters for the supported system sizes. The system
topology supports a 200 MB/s per processor bisection bandwidth from 32
processors to 512 processors.
• Each server or partition within the server must contain one system IX-brick that
provides the base I/O functionality.
• Each server supports up to eight I/O bricks.
• When the server contains a memory-only Cx-brick, the memory-only Cx-brick must
be paired with a Cx-brick that has at least four processors.
• You can configure your server as a single system, or you can divide it into partitions
that operate as separate systems. For example, you can configure an Origin 3900
server that has 512 processors as a single 512-processor system, or you can divide it
into as many as eight separate systems. The size of a partition can be configured to
match your job size. For more information about partitioning, see Partitioning for
Systems that Contain Cx-bricks (007-4426-00x).
• An Origin 3900 server is configured so that the server resides in the smallest
footprint possible and so that the Cx-bricks are placed low within the racks. The
number of compute racks is determined by the number of Cx-bricks, I/O bricks,
and storage bricks in the server. For example, the smallest footprint for a 10
Cx-brick system is two compute racks; however, if an additional rack is required to
house the I/O and storage bricks, a compute rack, rather than an I/O rack, is added
to the system. The Cx-bricks are placed low within the three compute racks and the
I/O and storage bricks are placed above the Cx-bricks (see Figure 2-5 and
Figure 2-6).
System Configurations
47