Lenovo System x3550 M5, Installation And Service Manual

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The following illustration shows the location of the DIMM connectors on the system board.
Figure 86. DIMM connectors location
DIMM installation sequence
Depending on the server model, the server may come with a minimum of one 2 GB or 4 GB DIMM installed
in slot 1. When you install additional DIMMs, install them in the order shown in the following table to
optimize system performance.
In general, all four channels on the memory interface for each microprocessor can be populated in any order
and have no matching requirements.
Table 27. Normal mode DIMM installation sequence
Number of installed
microprocessors
DIMM connector population sequence
One microprocessor installed
1, 4, 9, 12, 2, 5, 8, 11, 3, 6, 7, 10
Two microprocessors installed 1, 13, 4, 16, 9, 21, 12, 24, 2, 14, 5, 17, 8, 20, 11, 23, 3, 15, 6, 18, 7, 19, 10, 22
Memory mirrored channel
Memory mirrored channel mode replicates and stores data on two pairs of DIMMs within two channels
simultaneously.
If a failure occurs, the memory controller switches from the primary pair of memory DIMMs to the backup
pair of DIMMs. To enable memory mirrored channel through the Setup Utility, select
System Settings ➙
Memory . For more information, see “Using the Setup Utility” on page 36. When you use the memory
mirrored channel feature, consider the following information:
Chapter 5
.
Removing and replacing components
163