Skip to main content

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 server.

Independent memory mode guidelines:

  • Individual memory channels can run at different DIMM timings, but all channels must run at the same interface frequency.

  • Populate memory channel 0 first.

  • In each memory channel, populate slot 0 first.

  • Memory channel 1 is empty or identically populated as memory channel 0.

  • Memory channel 2 is empty or identically populated as memory channel 1.

  • If a memory channel has two DIMMs, populate the DIMM with a higher number of ranks in slot 0.

With one processor​

The following table shows the DIMM population sequence for independent memory mode when one processor is installed.

Note
When installing 2, 4, 6, or 12 DIMMs, refer to installation order for same-capacity DIMMs or for different-capacity DIMMs according the type of DIMMs you are installing. S stands for same-capacity while D stands for different capacity.
Table 1. Independent mode memory population sequence for one processor
TotalProcessor 1
DIMMs161514131211109 87654321
114 
2 (S)  14   10         
2 (D)1412
4 (S)†  14   10  7   3  
4 (D)*141253
6 (S)16 14   10  7   3 1
8†‡16141210 7531
12 (S)16151413  10987  4321
12 (D)*†‡16141312109875431
16†‡16151413121110987654321
Note
* Each of the following DIMM slot groups should be populated with DIMMS of the same capacity:

  • Group of DIMM slot 1, 2, 5, 6, 11, 12, 15, and 16.

  • Group of DIMM slot 3, 4, 7, 8, 9, 10, 13, and 14.

† Sub NUMA Clustering (SNC2) feature can only be enabled when DIMMs are populated in this specified sequence. The SNC2 feature can be enabled via UEFI.

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

With two processors​

The following tables show the DIMM population sequence for independent memory mode when two processors are installed.

Note
When installing 4, 8, 12, or 24 DIMMs, refer to installation order for same-capacity DIMMs or for different-capacity DIMMs according the type of DIMMs you are installing. S stands for same-capacity while D stands for different capacity.
Table 2. Independent mode memory population sequence for two processor
TotalProcessor 1
DIMMs161514131211109 87654321
214 
4 (S)  14   10         
4 (D)1412
8 (S)†  14   10  7   3  
8 (D)*141253
12 (S)16 14   10  7   3 1
16†‡161412107531
24 (S)16151413  10987  4321
24 (D)*†‡16141312109875431
32†‡16151413121110987654321
TotalProcessor 2
DIMMs3231302928272625 2423222120191817
230
4 (S)  30   26         
4 (D)3028
8(S)†  30   26  23   19  
8(D)*3028 2119
12 (S)32 30   26  23   19 17
16†‡3230282623211917
24 (S)32313029  26252423  20191817
24 (D)*†‡323029282625242321201917
32†‡32313029282726252423222120191817
Note
* Each of the following DIMM slot groups should be populated with DIMMS of the same capacity:

  • Group of DIMM slot 1, 2, 5, 6, 11, 12, 15, 16, 17, 18, 21, 22, 27, 28, 31, and 32.

  • Group of DIMM slot 3, 4, 7, 8, 9, 10, 13, 14, 19, 20, 23, 24, 25, 26, 29, and 30.

† Sub NUMA Clustering (SNC2) feature can only be enabled when DIMMs are populated in this specified sequence. The SNC2 feature can be enabled via UEFI.

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