Memory module installation rules and order

Memory modules must be installed in a specific order based on the memory configuration that you implement and the number of processors and memory modules installed in the server.

Supported memory types

For information on the types of memory module supported by this server, see Memory section in Technical Specifications.

Your server has 12 memory slots with 12 channels. For a list of supported memory options, see:

Lenovo ServerProven website.

Information about optimizing memory performance and configuring memory is available at the Lenovo Press website:

Memory - Lenovo Press

In addition, you can take advantage of a memory configurator, which is available at the following site:

Lenovo Enterprise Solutions Configurator (Memory Configurations)

Specific information about the required installation order of memory modules in your server based on the system configuration is shown below.

Memory modules and processors layout

Figure 1. Memory modules and processors layout

The memory-channel configuration table below shows the relationship between the processors, memory controllers, memory channels, and memory module slot numbers.

Table 1. Memory slot and channel identification

Processor

CPU

UMC No.

UMC2

UMC1

UMC5

UMC0

UMC4

UMC3

UMC9

UMC10

UMC6

UMC11

UMC7

UMC8

Channel No.

CH-F

CH-E

CH-D

CH-C

CH-B

CH-A

CH-G

CH-H

CH-I

CH-J

CH-K

CH-L

DIMM No.

12

11

10

9

8

7

6

5

4

3

2

1

Memory module installation guideline

• At least one DIMM is required. Install at least six DIMMs for good performance.

• Mixing DIMMs from different vendors is supported in a system.

• Mixing x4 and x8 DIMMs is not allowed in a system.

• Only one rank and two rank DIMM mixing is allowed in a system.

• When installing DIMMs with different capacity, install the DIMM with the highest capacity first.

• For best performance, the population recommends identical memory capacity and rank across all 12 channels.

Memory module installation order

The following table shows the DIMM population sequence.

Table 2. DIMM population sequence

Total DIMMs	CPU
	12	11	10	9	8	7		6	5	4	3	2	1
1 DIMM						7
2 DIMMs						7		6
4 DIMMs				9		7		6		4
6 DIMMs				9	8	7		6	5	4
8 DIMMs		11		9	8	7		6	5	4		2
10 DIMMs		11	10	9	8	7		6	5	4	3	2
12 DIMMs	12	11	10	9	8	7		6	5	4	3	2	1