HP ProLiant DL380 G5 Server - Manual (Page 46)

Hardware options installation 46
• Branch 1 contains banks B and D
Online spare FBDIMM configuration requirements (in addition to general configuration requirements):
• When only bank A is being used, it must be fully populated with dual-rank FBDIMMs.
• If banks A and C are being used, they must be fully populated.
• If installed, bank A and bank C must contain FBDIMMs with identical part numbers.
• If installed, bank B and bank D must also contain FBDIMMs with identical part numbers.
In online spare mode, FBDIMMs must be populated as specified in the following table:
Configuration Branch 0
Bank A
1A and 3A
Branch 0
Bank C
2C and 4C Branch 1
Bank B
5B and 7B Branch 1
Bank D
6D and 8D
1* X — — —
2 X X — —
3 X X X X
* Configuration 1 is only supported if using bank A, populated with dual-rank FBDIMMs.
After installing FBDIMMs, use RBSU to configure the system for online spare memory support
(" Configuring online spare memory " on page 64 ).
Mirrored memory configuration
Mirroring provides protection against uncorrectable memory errors that would otherwise result in server
downtime.
Mirroring is performed on the branch level. Branch 0 and branch 1 mirror each other.
Each branch maintains a copy of all memory contents. Memory writes go to both branches. Memory
reads come from only one of the two branches (unless an uncorrectable error occurs). If a memory read
on one branch returns incorrect data due to an uncorrectable memory error, the system automatically
retrieves the proper data from the other branch. A branch is not necessarily disabled (thus losing
mirroring protection) because of a single uncorrectable error. Mirroring protection is not lost because of
transient and soft uncorrectable errors, resulting in systems that maintain mirroring protection (and thus
improved uptime) unless there is a failure of both branches.
Mirrored memory FBDIMM configuration requirements (in addition to general configuration requirements):
• Banks A and B must be fully populated.
• Bank A and bank B must contain FBDIMMs with identical part numbers. If installed, bank C and
bank D must also contain FBDIMMs with identical part numbers.
When using mirrored memory mode, FBDIMMs must be populated as specified in the following table:
Configuration Bank A
1A and 3A
Bank B
5B and 7B Bank C
2C and 4C Bank D
6D and 8D
1 X X — —
2 X X X X
After installing FBDIMMs, use RBSU to configure the system for mirrored memory support (" Configuring
mirrored memory " on page 65 ).