Which DIMM Slots to Use?

When populating a dual in-line memory module (DIMM) board, it is important to populate the DIMM slots in the correct order. The recommended order is to populate the DIMM slots in the following sequence:

1. CPU 1 DIMM 1
2.

CPU 1 DIMM 2
3. CPU 2 DIMM 1
4. CPU 2 DIMM 2.

The reason for this recommended sequence is that it ensures an equal memory size and channel assignment for both CPUs. If the CPUs are not identical, then it is recommended to fill the DIMMslots for each CPU starting with the CPU with the least amount of L3 cache.

It is also important to note that when using registered DIMMs (RDIMMs), there are additional considerations for slot population. For example, when using 2-socket systems with 18-channel RDIMMs, it is recommended to populate in the following order:

1. CPU 1 Channel A1 and B1 DIMMs (DUO)
2. CPU 1 Channel A2 and B2 DIMMs (DUO)
3.

CPU 2 Channel A1 and B1 DIMMs (DUO)
4. CPU 2 Channel A2 and B2 DIMMs (DUO)
5. Repeat step 1 for the next two channels until all channels are populated on both CPUs.

The above sequence is designed to provide balanced memory channel utilization as well as balanced power consumption across all channels. This will help to ensure optimal performance and stability of the system.

In conclusion, when populating a dual in-line memory module board, it is important to populate the DIMM slots in the correct order. The recommended order is to populate the DIMM slots in the following sequence: CPU 1 DIMM 1, CPU 1 DIMM 2, CPU 2 DIMM 1, CPU 2 DIMM 2.

When using registered dimms, there are additional considerations for slot population which are designed to provide balanced memory channel utilization as well as balanced power consumption across all channels.