NEC Express5800/R120b-1 User Manual page 393

The 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 (described on page 4-2), 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 2-CPU
configuration configuration
2
4
2
4
2 3
1 1
2 3
1 1
The following LockStep cannot be configured:
LockStep between memory channels of different memory controllers (CPU)
LockStep within the same memory channel
Notes on configuring LockStep
In 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 LockStep
When you remove DIMMs that takes down the LockStep
FRONT
CPU2-DIMM 3
CPU2-DIMM 6
CPU2-DIMM 2
CPU2-DIMM 5
CPU2-DIMM 1
CPU2-DIMM 4
CPU2
CPU1
CPU1-DIMM 4
CPU1-DIMM 1
CPU1-DIMM 5
CPU1-DIMM 2
CPU1-DIMM 6
CPU1-DIMM 3
Upgrading Your Server 9-37
Mother board
REAR