IBM System x3300 M4 Installation And Service Manual page 424

v The maximum operating speed of the server is determined by the slowest
v A minimum of one DIMM must be installed for each microprocessor. For
v The server comes with a minimum of one DIMM installed in slot 1. When you
v The server supports independent mode, spare channel mode, and mirroring
v Independent mode: When you use the independent mode, install DIMMs as
v Spare channel mode: When you use the memory mirroring feature, consider the
v Memory-mirroring mode: When you use the memory mirroring feature,
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System x3300 M4 Type 7382: Installation and Service Guide
DIMM installed in the server.
example, you must install a minimum of two DIMMs if the server has two
microprocessors installed. That is, one for microprocessor 1 and one for
microprocessor 2.
install additional DIMMs, install them in the order shown in the information in
the following tables to optimize system performance.
mode.
indicated in the following tables.
– The following table lists the DIMM installation sequence for non-mirroring
mode when one or two microprocessors is installed in the server:
Table 28. DIMM population sequence (independent mode)
Number of installed
microprocessors
1
2
following information:
– In spare channel mode, one rank is a spare of the other ranks on the same
channel. The spare rank is held in reserve and is not available as system
memory. The spare rank must have identical or larger memory capacity than
all the other ranks (sparing source ranks) on the same channel. After sparing,
the sparing source rank will be lost.
– DIMMs must be installed in sets of three. The DIMMs in each set must be the
same size and type.
– The following table lists the DIMM installation sequence for rank sparing
mode when one or two microprocessors is installed in the server:
Table 29. DIMM population sequence (rank sparing mode)
Number of installed
microprocessors
1
2
consider the following information:
– Memory-mirroring mode replicates and stores data on two pairs of DIMMs
simultaneously. If a failure occurs, the memory controller switches from the
primary pair of memory DIMMs to the backup pair of DIMMs. This
mirroring provides redundancy in memory but reduces the total memory
DIMM connector population sequence
1, 3, 5, 2, 4, 6
1, 7, 3, 9, 5, 11, 2, 8, 4, 10, 6, 12
DIMM connector population sequence
1, 3, 5
2, 4, 6
1, 3, 5
7, 9, 11
2, 4, 6
8, 10, 12