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Independent memory mode

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 server.

Attention
Independent memory mode guidelines:

  • There should be at least one memory module per processor.

  • If only one DIMM is populated in a channel, populate it in the slot furthest away from CPU of that channel.

  • Always populate DIMMs with a higher electrical loading in slot 0 followed by slot 1.

    • When single or dual rank RDIMMs are populated for 2DPC, always populate the higher quantity rank DIMM first in the farthest DIMM slot, followed by the nearest DIMM slot.

    • If two DIMMs on a channel have identical ranks, then populate the one with the higher capacity on slot 0.

  • A maximum of 8 logical ranks (ranks seen by the host) per channel is allowed.

  • A maximum of two different types (capacity) is supported per system.

  • Channel A, C, E, G (DIMM slot 14, 13, 10, 9, 3, 4, 7, and 8) must be populated with the same total capacity per channel if populated.

  • Channel B, D, F, H (DIMM slot 16, 15, 12, 11, 1, 2, 5, and 6) must be populated with the same total capacity per channel if populated, but can be populated different from channel A, C, E, G (DIMM slot 14, 13, 10, 9, 3, 4, 7, and 8).

  • Memory population must be identical on all CPUs.

Note
When adding one or more DIMMs during a memory upgrade, you might need to remove some DIMMs that are already installed to new locations.

Independent memory mode with one processor and same capacity memory modules​

Table 1. Independent memory mode with one processor and same capacity memory modules
Total DIMMsProcessor 1Total DIMMs
12345678910111213141516
1141
2         10   14  2
4137101441
61 3   7  10   14 166
81,213571012141681,2
121234  78910  1314151612
161,212345678910111213141516161,2
Note

  1. DIMM configurations that support Sub NUMA Clustering (SNC), which can be enabled via UEFI.

  2. DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.

Independent memory mode with one processor and different capacity memory modules​

Table 2. Independent memory mode with one processor and different capacity memory modules
Total DIMMsProcessor 1Total DIMMs
12345678910111213141516
212142
4  3 5      12 14  4
81,213571012141681,2
121,21 345 78910 121314 16121,2
161,212345678910111213141516161,2
Note

  1. DIMM configurations that support Sub NUMA Clustering (SNC), which can be enabled via UEFI.

  2. DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.

Independent memory mode with two processors and same capacity memory modules​

Table 3. Independent mode with two processors and same capacity memory modules (processor 1)
Total DIMMsProcessor 1Total DIMMs
12345678910111213141516
2142
4         10   14  4
8137101481
121 3   7  10   14 1612
161,2135710121416161,2
241234  78910  1314151624
321,212345678910111213141516321,2
Table 4. Independent mode with two processors and same capacity memory modules (processor 2)
Total DIMMsProcessor 2Total DIMMs
17181920212223242526272829303132
2192
4  19   23         4
811923263081
1217 19   23  26   30 3212
161,21719212326283032161,2
2417181920  23242526  2930313224
321,217181920212223242526272829303132321,2
Note

  1. DIMM configurations that support Sub NUMA Clustering (SNC), which can be enabled via UEFI.

  2. DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.

Independent memory mode with two processors and different capacity memory modules​

Table 5. Independent mode with two processors and different capacity memory modules (processor 1)
Total DIMMsProcessor 1Total DIMMs
12345678910111213141516
412144
8  3 5      12 14  8
161,2135710121416161,2
241,21 345 78910 121314 16241,2
321,212345678910111213141516321,2
Table 6. Independent mode with two processors and different capacity memory modules (processor 2)
Total DIMMsProcessor 2Total DIMMs
17181920212223242526272829303132
419214
8  19 21      28 30  8
161,21719212326283032161,2
241,217 192021 23242526 282930 32241,2
321,217181920212223242526272829303132321,2
Note

  1. DIMM configurations that support Sub NUMA Clustering (SNC), which can be enabled via UEFI.

  2. DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.