Memory subsystem architecture, Single-rank and dual-rank dimms, Dimm identification – HP ProLiant XL220a Gen8 v2-Server User Manual
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Memory subsystem architecture
The memory subsystem in this server is divided into channels. The processor supports two channels, and each
channel supports two DIMM slots.
Channel
Population order
Slot number
1
C
A
4
3
2
D
B
2
1
DIMM slots are identified by number and by letter. Letters identify the population order. Slot numbers are
reported by ROM messages during boot and are used for error reporting. For the DIMM slot locations, see
)."
Single-rank and dual-rank DIMMs
DIMM configuration requirements are based on these classifications:
•
Single-rank DIMM—One set of memory chips that is accessed while writing to or reading from the
memory.
•
Dual-rank DIMM—Two single-rank DIMMs on the same module, with only one rank accessible at a time.
The server memory control subsystem selects the proper rank within the DIMM when writing to or reading
from the DIMM.
Dual-rank DIMMs provide the greatest capacity with the existing memory technology. For example, if current
DRAM technology supports 2-GB single-rank DIMMs, a dual-rank DIMM would be 4 GB.
DIMM identification
To determine DIMM characteristics, use the label attached to the DIMM and the following illustration and
table.