NEC express5800 A2010b User Manual page 197

Chapter 2 Preparations
(3)
Independent + Mirroring
In Independent + Mirroring mode, mirroring memory is added to Independent mode, and regularly copies the
contents of memory onto mirroring memory. If the memory error is detected, the mirroring memory takes over to
continue processing.
Mirroring is performed between SMI channels in memory controller, as shown in the figure below. In principle,
the SMI channel having younger number (SMI0) is defined as duplication origin.
RAS feature is higher than Independent mode and Independent + Rank Sparing mode, however, the memory
capacity available for OS is reduced to half of installed memory capacity.
Memory Riser #1
DIMM #1
DIMM #5
CH0
Memory Buffer #1
This feature can be used under the following conditions:
•
The DIMMs used for Mirroring Pair (DIMM#1/3, DIMM#2/4, DIMM#5/7, DIMM#6/8) between SMI channel
must be of the same model.
•
Note Combinations of channels 0 and 2, and 1 and 3 are used in Independent + Mirroring
mode.
•
Use NE3302-H030F/H031F/H032F/H033F additional memory for Independent +
Mirroring mode.
•
Use the DIMMs of same model for Mirroring PAIR.
DIMM #2
DIMM #6
CH1
SMI0
Memory Controller #1
Express5800/A1040b, A2040b, A2020b, A2010b User's Guide
1. Installing / Removing Internal Options
Mirroring memory
DIMM #3
DIMM #4
DIMM #7
DIMM #8
CH2 CH3
Memory Buffer #1
SMI1
Memory Controller #2
Processor
Mirroring
PAIR #1
Mirroring
PAIR #2
Mirroring
PAIR #3
Mirroring
PAIR #4
SMI2 SMI3
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