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DCPMM and DRAM DIMM installation order

For DCPMM, the following memory modes are available:
Note

  • Before installing DCPMMs and DRAM DIMMs, refer to DC Persistent Memory Module (DCPMM) setup and make sure to meet all the requirements.

  • To verify if the presently installed processors support DCPMMs, examine the four digits in the processor description. Only the processor with description meeting both of the following requirements support DCPMMs.

    • The first digit is 5 or a larger number.

    • The second digit is 2.

    Example: Intel Xeon 5215L and Intel Xeon Platinum 8280M

    Note
    The only exception to this rule is Intel Xeon Silver 4215, which also supports DCPMM.

  • DCPMMs are supported only by Intel Xeon SP Gen 2. For a list of supported processors and memory modules, see http://www.lenovo.com/us/en/serverproven/

  • When you install two or more DCPMMs, all DCPMMs must have the same Lenovo part number.

  • All DRAM memory modules installed must have the same Lenovo part number.

  • 16 GB RDIMM has two different types: 16 GB 1Rx4 and 16 GB 2Rx8. The part number of the two types are different.
  • Supported memory capacity range varies with the following types of DCPMMs.

    • Large memory tier (L): The processors with L after the four digits (for example: Intel Xeon 5215 L)

    • Medium memory tier (M): The processors with M after the four digits (for example: Intel Xeon Platinum 8280 M)

    • Other: Other processors that support DCPMMs (for example: Intel Xeon Gold 5222)

In addition, you can take advantage of a memory configurator, which is available at the following site:

Lenovo Enterprise Solutions Configurator (Memory Configurations)

The following illustration helps you to locate the memory module slots on the system board.
Figure 1. memory module slots on the system board
memory module slots on the system board

  • App Direct Mode
    In this mode, DCPMMs act as independent and persistent memory resources directly accessible by specific applications, and DRAM DIMMs act as system memory.
  • Memory Mode
    In this mode, DCPMMs act as volatile system memory, while DRAM DIMMs act as cache. Ensure that the ratio of DRAM DIMM capacity to DCPMM apacity is between 1:2 and 1:16.
  • Mixed Memory Mode
    In this mode, some percentage of DCPMM capacity is directly accessible to specific applications (App Direct), while the rest serves as system memory. The App Direct part of DCPMM is displayed as persistent memory, while the rest of DCPMM capacity is displayed as system memory. DRAM DIMMs act as cache in this mode.