Memory module installation rules and order
Memory modules must be installed in a specific order based on the memory configuration that you implement and the number of processors and memory modules installed in the server.
Supported memory types
For information on the types of memory module supported by this server, see Memory section in Technical Specifications.
Your server has 12 memory slots with 12 channels. For a list of supported memory options, see:
Information about optimizing memory performance and configuring memory is available at the Lenovo Press website:
In addition, you can take advantage of a memory configurator, which is available at the following site:
Lenovo Enterprise Solutions Configurator (Memory Configurations)
Specific information about the required installation order of memory modules in your server based on the system configuration is shown below.
Memory modules and processors layout
The memory-channel configuration table below shows the relationship between the processors, memory controllers, memory channels, and memory module slot numbers.
| Processor | CPU | ||||||||||||
| UMC No. | UMC2 | UMC1 | UMC5 | UMC0 | UMC4 | UMC3 | UMC9 | UMC10 | UMC6 | UMC11 | UMC7 | UMC8 | |
| Channel No. | CH-F | CH-E | CH-D | CH-C | CH-B | CH-A | CH-G | CH-H | CH-I | CH-J | CH-K | CH-L | |
| DIMM No. | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Memory module installation guideline
At least one DIMM is required. Install at least six DIMMs for good performance.
Mixing DIMMs from different vendors is supported in a system.
Mixing x4 and x8 DIMMs is not allowed in a system.
Only one rank and two rank DIMM mixing is allowed in a system.
When installing DIMMs with different capacity, install the DIMM with the highest capacity first.
For best performance, the population recommends identical memory capacity and rank across all 12 channels.
General DIMM mixing rules
| DIMMs | Coexist in a system |
| 9x4 RDIMM and other RDIMM types | x |
| 3DS RDIMM and other DIMM types | x |
| 128 GB 3DS RDIMM and 256 GB 3DS RDIMM | x |
| x4 DIMM and x8 DIMM | x |
| Different DRAM density (16Gbit, 24Gbit, and 32Gbit)1, 2 | x (for 9004 series processors) |
| RDIMMs of different capacity3, 4 | √ |
| RDIMMs of different ranks (1R and 2R)4 | √ |
| DIMMs manufactured by different vendors | √ |
Note
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Memory module installation order
The following table shows the DIMM population sequence.
| Total DIMMs | CPU | ||||||||||||
| 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | ||
| 1 DIMM | 7 | ||||||||||||
| 2 DIMMs | 7 | 6 | |||||||||||
| 4 DIMMs | 9 | 7 | 6 | 4 | |||||||||
| 6 DIMMs | 9 | 8 | 7 | 6 | 5 | 4 | |||||||
| 8 DIMMs | 11 | 9 | 8 | 7 | 6 | 5 | 4 | 2 | |||||
| 10 DIMMs | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | |||
| 12 DIMMs | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |