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.
Your server has 32 memory slots with 16 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)
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 1 | |||||||||||||||
| Controller | iMC3 | iMC2 | iMC0 | iMC1 | ||||||||||||
| Channel | CH1 | CH0 | CH1 | CH0 | CH0 | CH1 | CH0 | CH1 | ||||||||
| Slot No. | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
| DIMM No. | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 |
| Processor | CPU 2 | |||||||||||||||
| Controller | iMC3 | iMC2 | iMC0 | iMC1 | ||||||||||||
| Channel | CH1 | CH0 | CH1 | CH0 | CH0 | CH1 | CH0 | CH1 | ||||||||
| Slot No. | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
| DIMM No. | 32 | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 |
Slot No.: DIMM slot number in each memory channel. Each memory channel has two DIMM slots: slot 0 (furthest from the processor) and slot 1 (closest to the processor).
DIMM No.: DIMM slot number on the system board assembly. Each processor has 16 DIMM slots.
Memory module installation guideline
- For the installation rules and population sequence, see TruDDR5 DIMMs installation order.
At least one DIMM is required for each processor. Install at least eight DIMMs per processor for good performance.
When you replace a DIMM, the server provides automatic DIMM enablement capability without requiring you to use the Setup utility to enable the new DIMM manually.