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.
Memory channel 1 is empty or identically populated as memory channel 0.
Memory channel 2 is empty or identically populated as memory channel 1.
In each memory channel, populate slot 0 first.
If a memory channel has two DIMMs, populate the DIMM with a higher number of ranks in slot 0.

With two processors

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

Table 1. Independent mode with two processors
Total	Processor 1												Processor 2												Total
DIMMs	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	DIMMs
2								8												20					2
8*			3		5			8		10					15		17			20		22			8*
12*	1		3		5			8		10		12	13		15		17			20		22		24	12*
16*			3	4	5	6	7	8	9	10					15	16	17	18	19	20	21	22			16*
24*	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	24*

Note

DIMM configurations with an asterisk (*) listed in the table 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.

With four processors

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

Table 2. Independent mode with four processors
Total	Processor 1												Processor 2												Total
DIMMs	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	DIMMs
4								8												20					4
16*			3		5			8		10					15		17			20		22			16*
24*	1		3		5			8		10		12	13		15		17			20		22		24	24*
32*			3	4	5	6	7	8	9	10					15	16	17	18	19	20	21	22			32*
48*	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	48*
Total	Processor 3												Processor 4												Total
DIMMs	25	26	27	28	29	30	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48	DIMMs
4								32												44					4
16*			27		29			32		34					39		41			44		46			16*
24*	25		27		29			32		34		36	37		39		41			44		46		48	24*
32*			27	28	29	30	31	32	33	34					39	40	41	42	43	44	45	46			32*
48*	25	26	27	28	29	30	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48	48*

Note

Give documentation feedback

Independent memory mode installation order

With two processors​

With four processors​

With two processors

With four processors