Table 25. Advanced ECC (Lockstep)
Processor
Configuration
Memory population rules
Memory population information
Single CPU
Advanced ECC
(Lockstep)
{1,2}, {3,4}
Numbers inside the brackets indicate
the slots that must be populated in
pairs, odd amount of pairs allowed.
Dual CPU
NOTE:
Populate
round robin
starting with
CPU1
Advanced ECC
(Lockstep)
C1{1,2},C2{1,2},C1{3,4},C2{3,4}….
Numbers inside the brackets indicate
the slots that must be populated in
pairs, odd amount of pairs allowed.
NOTE:
Advanced ECC with mirroring is not supported.
Memory optimized (independent channel) mode
This mode supports Single Device Data Correction (SDDC) only for memory modules that use x4 device width. It does not impose any
specific slot population requirements.
Table 26. Memory optimized (independent channel) mode
Processor
Configuration
Memory population rules
Memory population
information
Single CPU
NOTE:
Optimized mode permits
unbalanced configurations, eg, 1:1:1:0
DIMM per channel (DPC) combinations.
Optimized (independent
channel)
1, 2, 3, 4
Populate in this order,
odd amount of DIMMs
per CPU allowed.
Dual CPU
NOTE:
Populate round robin starting with
CPU1:
NOTE:
Optimized mode permits
unbalanced configurations, eg, 2:1:1:1 DPC
combinations.
Optimized (independent
channel)
C1{1}, C2{1}, C1{2}, C2{2},
C1{3}, C2{3}…
Populate in this order,
odd amount of DIMMs
per CPU allowed.
Memory mirroring
Memory mirroring offers the strongest memory module reliability mode compared to all other modes, providing improved uncorrectable
multi-bit failure protection. In a mirrored configuration, the total available system memory is one half of the total installed physical memory.
Half of the installed memory is used to mirror the active memory modules. In the event of an uncorrectable error, the system switches
over to the mirrored copy. This ensures SDDC and multi-bit protection.
The installation guidelines for memory modules are as follows:
•
Memory modules must be identical in size, speed, and technology.
•
DIMMs installed in memory sockets with white release tabs must be identical and similar rule applies for sockets with black release
tabs. This ensures that identical DIMMs are installed in matched pairs—for example, A1 with A2, A3 with A4.
NOTE:
Mirroring and Advanced ECC modes require minimum of two DIMMs per CPU and must be populated in pairs of either
two or four DIMMs per CPU.
Installing and removing sled components
57
