NEC Express5800/R120g-2M User Manual page 66

Chapter 2 Preparations
Memory Lock Step feature can be used under the following conditions:

Install DIMMs in DIMM slots to configure a Lock Step set.

All the installed DIMMs should have the same capacity.

Run BIOS Setup Utility (SETUP), change parameters as shown below, save the settings, and exit.
Advanced  Memory Configuration  Memory RAS Mode  LockStep
Server  Power Measurement Policy  One Time

After restart, run SETUP again, and check if "Lock Step" is displayed for the following parameter.
Advanced  Memory Configuration  Memory Information  CPUx_DIMMx Status

Installation order depends on CPU configuration. See the figure below.
1CPU 構成 1CPU 2CPU 構成 2CPU
configuration 搭載順序 configuration 搭載順序
2 3
4
7
6 11
2 3
4 7
6 11
5 9
3 5
1 1
5 9
3 5
1 1
4
8
12
4
8
12
10
6
2
10
6
2
Memory Lock Step cannot be configured in the following cases:

Memory Lock Step between memory channels of different memory controllers (CPU)

Memory Lock Step within the same memory channel
Notes on Configuring Lock Step
In Memory Lock Step configuration, Memory RAS Mode menu is changed from "Lock Step" to "Independent"
in the following cases:

When you additionally install DIMMs that unable to configure Memory Lock Step

When you remove DIMMs that takes down Memory Lock Step
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CPU1_DIMM 3
CPU1_DIMM 7
CPU1_DIMM 11
CPU1_DIMM 4
CPU1_DIMM 8
CPU1_DIMM 12
CPU1_DIMM 10
CPU1_DIMM 6
CPU1_DIMM 2
CPU1_DIMM 9
CPU1_DIMM 5
CPU1_DIMM 1
CPU2_DIMM 3
CPU2_DIMM 7
CPU2_DIMM 11
CPU2_DIMM 4
CPU2_DIMM 8
CPU2_DIMM 12
CPU2_DIMM 10
CPU2_DIMM 6
CPU2_DIMM 2
CPU2_DIMM 9
CPU2_DIMM 5
CPU2_DIMM 1
Express5800/R120g-2M User's Guide
1. Installing Internal Optional Devices