IBM System x3850 X5 Implementation Manual page 87

Tip: The QPI Wrap Cards are only for single-node configurations with three or four
processors installed. They are
Single-node configurations with two processors
Configurations with MAX5 memory expansion units
Two-node configurations
Figure 3-8 shows the QPI Wrap Card.
Figure 3-8 QPI Wrap Card
For single-node systems with three or four processors installed, but without the MAX5
memory expansion unit connected, install two QPI Wrap Cards. Figure 3-9 shows a diagram
of how the QPI Wrap Cards are used to complete the QPI mesh. Although the QPI Wrap
Cards are not mandatory, they provide a performance boost by ensuring that all CPUs are
only one hop away from each other, as shown in Figure 3-9.
Figure 3-9 Location of QPI Wrap Cards
not necessary
for any of the following items:
QPI
ports
QPI QPI
SMI
links
Intel Intel
Xeon Xeon
CPU 3 CPU 4
QPI
links
Intel Intel
Xeon Xeon
CPU 1 CPU 2
QPI QPI
QPI
ports
Chapter 3. IBM System x3850 X5 and x3950 X5
QPI Wrap Card
connection
External
QPI ports
External
QPI ports
QPI Wrap Card
connection
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