Independent memory mode installation order
In independent memory mode, memory channels can be populated with DIMMs in any order and you can populate all channels for each processor in any order with no matching requirements. Independent memory mode provides the highest level of memory performance, but lacks failover protection. The DIMM installation order for independent memory mode varies based on the number of processors and memory modules installed in the node.
Memory module installation order in independent mode
Follow the rules below when installing memory modules in independent mode:
All memory modules must be DDR5 memory modules.
At least one DDR5 DIMM is required per installed processor.
All DDR5 DIMM must operate at the same speed in the same node.
Memory population must be identical between processors.
Memory modules from different vendors are supported.
In each memory channel, populate the slot farthest from the processor (slot 0) first.
Mixing x8 and x4 DIMM is not supported in a node.
All the installed memory modules must be of the same type.
System hang on POST may occur on a server operating in this configuration. In this case, contact Lenovo service to replace the failed DIMM for proper operation.
With one processor
The following table shows the DIMM population sequence for independent memory mode when one processor is installed.
| Total DIMMs | Processor 1 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | ||
| 1 | 4 | ||||||||
2 * |
| 7 |
|
| 4 |
|
|
| |
| 4* | 7 | 5 | 4 | 2 | |||||
| 6 |
| 7 | 6 | 5 | 4 |
| 2 | 1 | |
| 8 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
Note * When there are two or four DIMMs installed per processor, 24 GB or 48 GB DIMMs are not supported. | |||||||||
With two processors
The following tables show the DIMM population sequence for independent memory mode when two processors are installed.
| Total DIMMs | Processor 1 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | ||
| 2 | 4 | ||||||||
| 4* |
| 7 |
|
| 4 |
|
|
| |
| 8* | 7 | 5 | 4 | 2 | |||||
| 12 |
| 7 | 6 | 5 | 4 |
| 2 | 1 | |
| 16 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
| Total DIMMs | Processor 2 | ||||||||
| 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | ||
| 2 | 13 | ||||||||
| 4* |
| 10 |
|
| 13 |
|
|
| |
| 8* | 10 | 12 | 13 | 15 | |||||
| 12 |
| 10 | 11 | 12 | 13 |
| 15 | 16 | |
| 16 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | |
Note * When there are two or four DIMMs installed per processor, 24 GB or 48 GB DIMMs are not supported. | |||||||||