User's Guide

1. Installing Internal Optional Devices
Express5800/R120d-1M User’s Guide
70
Chapter 2 Preparations
(3) Memory Sparing Feature
Memory Sparing feature puts a memory channel 2 of a memory controller in each CPU into standby status as
spare devices. If a correctable error occurs in a DIMM in the running memory controller, the feature
automatically changes the running DIMM from the failed one to a DIMM in the standby state to continue the
processing.
Note
To use Memory Sparing feature, install N8102-476/477/499/500 additional memory board
(three DIMMs of same model).
Tips
The operating system recognizes the DIMMs as those with capacities less than the actual
physical capacities. (The recognized capacities vary depending on the number of DIMMs
and the physical capacity per DIMM.)
The following table shows configuration allowable for memory sparing and system logical memory capacity.
Number of
CPUs
Number of
DIMMs
Capacity of DIMM installed
2GB 4GB 8GB 16GB
1 3 4GB 8GB 20GB 40GB
6 8GB 16GB 40GB 80GB
9 12GB 24GB 60GB 120GB
12 16GB 32GB 80GB 160GB
2 6 8GB 16GB 40GB 80GB
12 16GB 32GB 80GB 160GB
18 24GB 48GB 120GB 240GB
24 32GB 64GB 160GB 320GB