HP ProLiant ML370 G5 Server - Manual (Page 44)

Hardware options installation 44
Memory board 1
configuration Bank A
1A and 5A Bank B
2B and 6B Bank C
3C and 7C Bank D
4D and 8D
4 X X X X
Dual memory board configuration:
Memory board 1
configuration
Memory board 2
configuration Bank A
1A and 5A Bank B
2B and 6B Bank C
3C and 7C Bank D
4D and 8D
1 X
—
—
— —
— —
—
2 X
X
—
— —
— —
—
3 X
X
X
— —
— —
—
4 X
X
X
X —
— —
—
5 X
X
X
X X
— —
—
6 X
X
X
X X
X —
—
7 X
X
X
X X
X X
—
8 X
X
X
X X
X X
X
Online spare memory
Online spare memory provides protection against degrading FBDIMMs by reducing the likelihood of
uncorrectable memory errors. This protection is available without any operating system support.
An understanding of single-rank and dual-rank FBDIMMs is required to understand memory usage in
online spare mode. FBDIMMs can either be single-rank or dual-rank. Certain FBDIMM configuration
requirements are based on these classifications. A dual-rank FBDIMM is similar to having two single-rank
FBDIMMs on the same module. Although only a single FBDIMM module, a dual-rank FBDIMM acts as two
separate FBDIMMs. The purpose of dual-rank FBDIMMs is to provide the largest capacity FBDIMM for the
current DRAM technology. If the current DRAM technology allows for 2-GB single-rank FBDIMMs, a dual-
rank FBDIMM using the same technology would be 4-GB.
In online spare mode, a single rank of memory acts as the spare memory. For single-rank FBDIMMs, the
entire FBDIMM acts as the spare memory. For a dual-rank FBDIMM, only half of the FBDIMM acts as the
spare memory while the other half is available for operating system and application usage.