Lenovo x3530 M4 Installation And Service Manual page 51

• The maximum operating speed of the server is determined by the slowest DIMM installed in the server.
• A minimum of one DIMM must be installed for each microprocessor. For 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.
• The server comes with a minimum of one DIMM installed in slot 1. When you install additional DIMMs,
install them in the order shown in the information in the following tables to optimize system performance.
• The server supports independent mode, spare channel mode, and mirroring mode.
• Independent mode: When you use the independent mode, install DIMMs as 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 6. DIMM population sequence (independent mode)
Number of installed
microprocessors
1
2
• Spare channel mode: When you use the memory mirroring feature, consider the 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 7. DIMM population sequence (rank sparing mode)
Number of installed
microprocessors
1
2
• Memory-mirroring mode: When you use the memory mirroring feature, 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 capacity to
one third. Channel 1 DIMM connectors 3, 4, 9, and 10 are not used in memory-mirroring mode. To
enable memory mirroring through the Setup utility, select System Settings ® Memory. For more
information, see "Using the Setup utility" on page 83.
– DIMMs must be installed in pairs. The DIMMs in each pair must be the same size and type.
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
.
Chapter 2 Installing optional devices
37