1. Installing Internal Optional Devices
Express5800/B120f User's Guide
54
Chapter 2 Preparations
(3)
Memory Sparing Feature
Memory Sparing feature defines one of the ranks in a memory channel under a memory controller of each CPU
into standby status as spare devices. If a correctable error occurs in a DIMM in the running memory channel,
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 the corresponding additional memory board
(two DIMMs of same model).
•
DIMMs installed in the system must be of the same model number.
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 allowable configuration for memory sparing and system logical memory capacity.
Number
of CPUs
Number of
DIMMs
Capacity of DIMM installed
8 GB (Dual Rank)
16 GB (Dual Rank)
32 GB (Quad Rank)
1
2
12 GB
24 GB
56 GB
4
24 GB
48 GB
112 GB
6
36 GB
72 GB
168 GB
2
4
24 GB
48 GB
112 GB
8
48 GB
96 GB
224 GB
12
72 GB
144 GB
336 GB
