NEC N8100-1668F User Manual page 393

The memory LockStep feature can be used under the following conditions:
Install two DIMMs that operate in parallel in memory socket.

All the installed DIMMs should have the same capacity.

Run SETUP (see Chapter 4), change parameters appropriately in the menu selected as

shown below, save the settings and exit from SETUP.
Select [Advanced] → [Memory Configuration] → [Memory RAS Mode] → [Lock Step].
After SETUP finishes, rerun SETUP and make sure that the installed DIMM status is

[Lock Step].
Install memory devices in the following order:

1-CPU
configuration
3rd
6th
2nd
5th
1st
4th
The following memory LockStep cannot be configured:
Memory LockStep between memory channels of different memory controllers (CPU)

Memory LockStep within the same memory channel

Notes on configuring memory LockStep
In memory LockStep configuration, [Memory RAS Mode] menu is changed from "LockStep" to
"Independent" in the following cases:
When you additionally install DIMMs that unable to configure memory LockStep

When you remove DIMMs that takes down the memory LockStep

REAR
Upgrading Your Server 9-49
2-CPU
FRONT
configuration
5th
11th
3rd
9th
1st
7th
8th
2nd
10th
4th
12th
6th