NEC Express5800/R120g-2M User Manual page 68

Chapter 2 Preparations
Standby
Running
Standby
Running
Memory Sparing feature can be used under the following conditions:

Install DIMMs in DIMM slots to configure a spare set.

DIMMs to be installed should have the same capacity.

Run BIOS Setup Utility (SETUP), change parameters as shown below, save settings, and exit.
Advanced  Memory Configuration  Memory RAS Mode  Sparing
Server  Power Measurement Policy  One Time

After restart, run SETUP again, and check if "Spared" is displayed for the following parameter.
Advanced  Memory Configuration  Memory Information  CPUx_DIMMx Status

Installation order depends on CPU configuration. See the figure below.
68
Memory controller
Spare set Spare set
#1 #3
Memory controller
Spare set Spare set
#2 #4
Express5800/R120g-2M User's Guide
1. Installing Internal Optional Devices
Spare set Spare set
#5 #7
Spare set Spare set
#6 #8