RDIMM independent memory mode installation order

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.

Memory installation guidelines

At least one DIMM is required for each processor.
Memory population must be identical between processors.
If only one DIMM is used per channel, it must be placed in the farthest slot (slot 0) from the CPU.
All DDR5 DIMMs installed must be of the same type, capacity, density, rank, and data width.
All DDR5 DIMMs must operate at the same speed in the same system.

With two processors

The following table shows the sequence of populating memory modules for independent mode when two processors are installed.

Table 1. Independent mode with two processors
Total DIMMs	Processor 1
Total DIMMs	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1
2 DIMMs							10
8 DIMMs³			14				10			7				3
8 DIMMs^{opt., 3}	16				12							5				1
16 DIMMs^{3, 4}	16		14		12		10			7		5		3		1
32 DIMMs^{3, 4}	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1
Total DIMMs	Processor 2
Total DIMMs	32	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17
2 DIMMs							26
8 DIMMs³			30				26			23				19
8 DIMMs^{opt., 3}	32				28							21				17
16 DIMMs^{3, 4}	32		30		28		26			23		21		19		17
32 DIMMs^{3, 4}	32	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17

Note

Supported DIMM capacities and types vary depending on the total number of DIMMs installed:
- 2 DIMMs: 32 GB or 64 GB RDIMMs
- 8 DIMMs: 64 GB RDIMMs
- 16 DIMMs: 64/96/128 GB RDIMMs or 256 GB 3DS RDIMMs
- 32 DIMMs: 64/96/128 GB RDIMMs or 256 GB 3DS RDIMMs
All DIMMs populated must be of the same type and the same capacity.
^opt.: An optional installation order for the DIMM configuration. For optimal performance, you are recommended to install DIMMs in the standard installation order. The optional installation order is used only for special requirements.
DIMM configurations that support the Sub NUMA Clustering (SNC) feature, which can be enabled via UEFI. SNC is not supported if DIMM population does not follow the sequence indicated by the table above.
DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.

With four processors

The following table shows the sequence of populating memory modules for independent mode when four processors are installed.

Table 2. Independent mode with four processors
Total DIMMs	Processor 1
Total DIMMs	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1
4 DIMMs							10
16 DIMMs³			14				10			7				3
16 DIMMs^{opt., 3}	16				12							5				1
32 DIMMs^{3, 4}	16		14		12		10			7		5		3		1
64 DIMMs^{3, 4}	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1
Total DIMMs	Processor 2
Total DIMMs	32	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17
4 DIMMs							26
16 DIMMs³			30				26			23				19
16 DIMMs^{opt., 3}	32				28							21				17
32 DIMMs^{3, 4}	32		30		28		26			23		21		19		17
64 DIMMs^{3, 4}	32	31	30	29	28	27	26	25	24	23	22	21	20	19	18	17
Total DIMMs	Processor 3
Total DIMMs	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48
4 DIMMs										42
16 DIMMs³			35				39			42				46
16 DIMMs^{opt., 3}	33				37							44				48
32 DIMMs^{3, 4}	33		35		37		39			42		44		46		48
64 DIMMs^{3, 4}	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48
Total DIMMs	Processor 4
Total DIMMs	49	50	51	52	53	54	55	56	57	58	59	60	61	62	63	64
4 DIMMs										58
16 DIMMs³			51				55			58				62
16 DIMMs^{opt., 3}	49				53							60				64
32 DIMMs^{3, 4}	49		51		53		55			58		60		62		64
64 DIMMs^{3, 4}	49	50	51	52	53	54	55	56	57	58	59	60	61	62	63	64

Note

Supported DIMM capacities and types vary depending on the total number of DIMMs installed:
- 4 DIMMs: 32 GB or 64 GB RDIMMs
- 16 DIMMs: 64 GB RDIMMs
- 32 DIMMs: 32/64/96/128 GB RDIMMs or 256 GB 3DS RDIMMs
- 64 DIMMs: 32/64/96/128 GB RDIMMs or 256 GB 3DS RDIMMs
All DIMMs populated must be of the same type and the same capacity.
^opt.: An optional installation order for the DIMM configuration. For optimal performance, you are recommended to install DIMMs in the standard installation order. The optional installation order is used only for special requirements.
DIMM configurations that support the Sub NUMA Clustering (SNC) feature, which can be enabled via UEFI. SNC is not supported if DIMM population does not follow the sequence indicated by the table above.
DIMM configurations that support Software Guard Extensions (SGX), see Enable Software Guard Extensions (SGX) to enable this feature.

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RDIMM independent memory mode installation order

Memory installation guidelines​

With two processors​

With four processors​

Memory installation guidelines

With two processors

With four processors