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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.

Normal mode DIMM installation sequence

In general, all four channels on the memory interface for each microprocessor can be populated in any order and have no matching requirements.

Table 1. Normal mode DIMM installation sequence
Number of installed microprocessorDIMM connector population sequence
One microprocessor installed1, 4, 9, 12, 2, 5, 8, 11, 3, 6, 7, 10
Two microprocessors installed1, 13, 4, 16, 9, 21, 12, 24, 2, 14, 5, 17, 8, 20, 11, 23, 3, 15, 6, 18, 7, 19, 10, 22

For optimal performance:

Make sure all four memory channels of each microprocessor are populated. Each memory channels should be populated with the same type and amount of memory per channel. Each microprocessor socket should be populated with the same type and amount of memory per socket. 1DPC (one DIMM per channel) or 2DPC (two DIMM per channel) memory configuration are recommended. Unless there is a need for memory capacity over memory frequency, 3DPC (three DIMMs per channel) configuration is not recommended since 3DPC configuration forces the memory subsystem to run at a lower frequency (1066MHz).

Flash DIMM installation sequence

  1. When you install 2 DIMMs per channel as the following installation sequence, the memory runs at 1600 MHz.
    Table 2. Flash DIMM installation sequence
    DIMM typeDIMM connector population sequence
    Flash DIMM5, 8, 17, 20
    RDIMM1, 4, 9, 12. 13, 16, 21, 24
  2. When you install 2 DIMMs (1 Flash DIMM and 1 RDIMM) per channel as the following installation sequence, the memory runs at 1333 MHz.
    Table 3. Flash DIMM installation sequence
    DIMM typeDIMM connector population sequence
    Flash DIMM2, 5, 8, 11. 14, 17, 20, 23
    RDIMM1, 4, 9, 12. 13, 16, 21, 24
  3. When you install 3 DIMMs (1 Flash DIMM and 2 RDIMMs) per channel as the following installation sequence, the memory runs at 1066 MHz.
    Table 4. Flash DIMM installation sequence
    DIMM typeDIMM connector population sequence
    Flash DIMM3, 6, 7, 10. 15, 18, 19, 22
    RDIMM1, 2, 4, 5, 8, 9, 11, 12, 13, 14, 16, 17, 20, 21, 23, 24

Please refer to the Understanding and Optimizing Memory Performance for Intel Xeon Processor E5-2600 Series in IBM Flex System, System x, and BladeCenter Platforms white paper for the detail.