Lenovo System x3750 M4, Installation And Service Manual

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Table 7. DIMM connectors associated with each microprocessor (continued)
Microprocessor Location
DIMM connectors associated with
the microprocessor
Microprocessor 3 Microprocessor and memory
expansion tray 25 through 36
Microprocessor 4 Microprocessor and memory
expansion tray 37 through 48
• When you replace a DIMM, the server provides automatic DIMM enablement capability without requiring
you to use the Setup utility to enable the new DIMM manually.
• The maximum operating speed of the server is determined by the slowest DIMM in the server.
• DIMMs do not have to be installed in pairs, except in memory-mirroring mode.
• 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 (one for each microprocessor). If you
install four microprocessors in the server, you must install a minimum of four DIMMs (one DIMM for
each microprocessor). For more information about the DIMM population sequence, see Table 8 “DIMM
population sequence for non-mirroring mode (independent mode)” on page 48, Table 9 “DIMM population
sequence for memory mirroring mode” on page 49, and Table 10 “DIMM population sequence for
memory sparing mode” on page 50.
Notes:
– When one DIMM per microprocessor is installed, system performance can be slow.
– To run VMware, one DIMM per microprocessor must be installed. If a DIMM is not installed for each
microprocessor, the server will not be able to boot VMware.
– For best performance, install DIMMs evenly across all four memory channels for each microprocessor.
• The server supports non-mirroring mode, memory mirroring mode, and memory sparing mode. For
more information and the DIMM population for non-mirroring mode, see “Non-mirroring (independent
mode)” on page 48. For more information and the DIMM population sequence for memory mirroring,
see “Memory mirroring” on page 49. For more information and the DIMM population sequence for
memory sparing, see “Memory sparing” on page 50.
Non-mirroring (independent mode)
This section contains information pertaining to the non-mirrored-channel mode of operation.
Note: When you install an optional microprocessor and memory expansion tray in the server,
microprocessors 3 and 4 must be installed as a pair. The server does not support a configuration of three
microprocessors.
The following table shows the DIMM population sequence for the non-mirrored channel mode of operation.
Table 8. DIMM population sequence for non-mirroring mode (independent mode)
Number of
installed
microprocessors
DIMM connector population sequence on
the system board
DIMM connector population sequence on
the microprocessor and memory expansion
tray
1 1, 12, 4, 9, 2, 11, 5, 8, 3, 10, 6, 7
2 1, 13, 12, 24, 4, 16, 9, 21, 2, 14, 11, 23, 5, 17,
8, 20, 3, 15, 10, 22, 6, 18, 7, 19
4 1, 13, 12, 24, 4, 16, 9, 21, 2, 14, 11, 23, 5, 17,
8, 20, 3, 15, 10, 22, 6, 18, 7, 19 25, 37, 36, 48, 28, 40, 33, 45, 26, 38, 35, 47,
29, 41, 32, 44, 27, 39, 34, 46, 30, 42, 31, 43
48
Lenovo System x3750 M4 Installation and Service Guide