NEC EXP804 User Manual page 81

Chapter 2 Preparations
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Use DIMMS with the same product number for the device.
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Mount DIMMs in the DIMM socket that constitutes the spare set.
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Change the following parameters and save them.
From System Utility, set "System Configuration > BIOS/Platform Configuration (RBSU) >System
Options > Memory Oprations > Advanced Memory Protection" to "Online Spare with Advanced ECC
Support".
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After rebooting, confirm "Advanced Memory Protection Mode：Online Spare with Advanced ECC" is
displayed in POST.
The following memory sparrings cannot be constructed.
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Mounting DIMMs with different product numbers on the spare set
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Memory sparing between different memory channels
Notes for the configuration of memory sparing
Even if you set "Advanced Memory Protection" to "Online Spare with Advanced ECC Support" and
select memory sparing configuration, in case DIMM configuration which cannot constitute memory
sparing due to expansion or removal of DIMM is detected, "Advanced Memory Protection" operates
as "Advanced ECC".
In this case,"Advanced ECC" is displayed in POST's "Advanced Memory Protection Mode".
IML also records the relevant error events.
Notes for replacements at failure
At the time of failure, identify damaged DIMM(s) from IML and replace DIMM(s) one by one.
(3) Fault tolerant memory function (ADDDC)
In case of failures in two chips of more than one memory and chip that are mounted in DIMM, the fault
tolerant function (ADDDC) automatically recovers the data and enables the system to continuously run.
The conditions to use this function are described below.
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Change the following parameters and save the settings.
From the System Utilities, select "System Configuration > BIOS/Platform Configuration (RBSU) >
System Options > Memory Operations to set Advanced Memory Protection to Fault Tolerant Memory
(ADDDC)".
●
After restarting, check that "Advanced Memory Protection Mode: Fault Tolerant Memory (ADDDC)"
appears on POST.

Note When using Memory Sparing Function, mount 8 or 12 DIMMs per CPU.

Use memories with the same product number for the device.
Tips Mount DIMM according to 1.10.2 DIMM installation order.
The operation system recognizes as the same size as the one actually mounted.
Express5800/R120h-1M User's Guide
1. Installing Internal Optional Devices
81