NEC express5800 A2010b - Page 197

1. Installing / Removing Internal Options
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.
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.
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.
DIMM #1
DIMM #5
DIMM #2
DIMM #6
CH0
CH1
SMI0
SMI2
SMI3
DIMM #3
DIMM #7
DIMM #4
DIMM #8
CH2
CH3
SMI1
Mirroring memory
M
emory Riser #1
Mirroring
PAIR #2
Mirroring
PAIR #3
Mirroring
PAIR #4
Memory Buffer #1
Memory Buffer #1
Memory Controller #1
Memory Controller #2
Processor
Mirroring
PAIR #1
Express5800/A1040b, A2040b, A2020b, A2010b User's Guide
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