Lenovo ThinkSystem SR650 Series Setup Manual page 145

• "DRAM DIMM installation rules" on page 141
• "DCPMM and DRAM DIMM installation order" on page 145
DRAM DIMM installation rules
For RDIMMs or LRDIMMs, the following memory modes are available:
• "Independent mode" on page 141
• "Mirroring mode" on page 143
• "Rank sparing mode" on page 144
The following illustration helps you to locate the memory module slots on the system board.
Note: It is recommended to install memory modules with the same rank in each channel.
Figure 80. memory module slots on the system board
Independent mode
Independent mode provides high performance memory capability. You can populate all channels with no
matching requirements. Individual channels can run at different memory module timings, but all channels
must run at the same interface frequency.
Notes:
• All memory modules to be installed must be the same type.
• When you install memory modules with same rank and different capacity, install the memory module that
has the highest capacity first.
The following table shows the memory module population sequence for independent mode when only one
processor (Processor 1) is installed.
Notes:
• If there are three identical memory modules to be installed for Processor 1, and the three memory
modules have the same Lenovo part number, move the memory module to be installed in slot 8 to slot 1.
• If there are ten identical memory modules to be installed for Processor 1, and the ten memory modules
have the same Lenovo part number, move the memory module to be installed in slot 6 to slot 12.
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Chapter 3 Server hardware setup
141