HP DL380 - Manual (Page 33)

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
*NOTE: 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 57).
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 due to transient and soft
uncorrectable errors, resulting in systems that maintain mirroring protection (and thus improved uptime) unless there is a true FBDIMM
failure.
Because both branches are active, concurrent reads from both branches at the same time are possible. Therefore, mirroring provides
superior read performance compared to all other Advanced Memory Protection modes.
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
NOTE: After installing FBDIMMs, use RBSU to configure the system for mirrored memory support ("Configuring mirrored memory" on
page 57).
QuickSpecs
HP ProLiant DL380 Generation 5
Memory
DA - 12477 Worldwide QuickSpecs — Version 1 — 6/26/2006 Page 33