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Memory module installation rules

Memory modules must be installed in a specific order based on the memory configuration that you implement on your server.

Your server has 16 memory slots and supports:

  • Minimum: 8 GB

  • Maximum: 2 TB

  • Type (depending on the model):

    • TruDDR4 2933, single-rank or dual-rank, 8 GB/16 GB/32 GB/64 GB RDIMM

    • TruDDR4 3200, dual-rank, 16 GB/32 GB/64 GB RDIMM

    • TruDDR4 2933, quad-rank, 128 GB 3DS RDIMM

    • TruDDR4 3200, quad-rank, 128 GB 3DS RDIMM (Only 7003 series processors are supported.)

For a list of supported memory options, see: Lenovo ServerProven website
Follow the below rules when you install or replace a memory module:

  • Memory modules in your server must be the same type.

  • Memory modules from different vendors are supported.

  • Memory modules with different capacities are supported. Install the memory module that has the higher capacity first.

  • Memory modules with different ranks are supported. Install the memory module with the highest rank first.

  • Do not mix x4 and x8 DIMMs in the same channel.

  • DIMMs of 3200 MHz and 2933 MHz are supported:

    • 2933 MHz DIMMs: operate at 2933 MHz for both 1 DIMM per channel and 2 DIMMs per channel

    • 3200 MHz DIMMs: operate at 3200 MHz when 1 DIMM per channel, but operate at 2933 MHz when 2 DIMMs per channel

    • Mixing of 2933 MHz and 3200 MHz DIMMs are supported in different channels, operating at 2933 MHz.

    Note
    Operating speed depends on the processor model. If the processor only supports a memory bus speed of 2666 MHz, all the installed DIMMs operate at 2666 MHz.

  • Install a memory module filler if there is no memory module installed in the slot.

The following illustration helps you to locate the memory slots on the system board.
Figure 1. DIMM locations
DIMM locations on the system board
The following table shows the relationship between the processors, memory controllers, memory channels, slots, and DIMM numbers. The system has eight channels, and supports up to two DIMMs per channel. DIMMs must be populated from farthest slot (slot 1) to closest slot (slot 0) to the processor on a per-channel basis when a data bus daisy chain topology is used. DIMMs may be populated in either slot on a per-channel basis when a data bus balanced tee route topology is used.
Table 1. DIMM installation order
Unified Memory Controller (UMC)UMC2UMC3UMC1UMC0UMC6UMC7UMC5UMC4
Channel (CH)DCBAEFGH
CH slot1010101001010101
DIMM number12345678910111213141516
1 DIMM3
2 DIMMs1 3             
3 DIMMs1314
4 DIMMs1 3          14 16
5 DIMMs1371416
6 DIMMs1 3 5 7      14 16
7 DIMMs1357101416
8 DIMMs1 3 5 7  10 12 14 16
9 DIMMs1345710121416
10 DIMMs12345 7  10 12 14 16
11 DIMMs1234571012131416
12 DIMMs12345 7  10 1213141516
13 DIMMs1234578101213141516
14 DIMMs12345678 10 1213141516
15 DIMMs123456789101213141516
16 DIMMs12345678910111213141516
Note
There are performance-optimized 6-DIMM and 12-DIMM configurations for server models with 7003 series CPU. For details, see the table below.
DIMM QtyDIMM population order
61, 3, 7, 10, 14, 16
121, 2, 3, 4, 7, 8, 9, 10, 13, 14, 15, 16