Single-, Dual-, And Quad-Rank Dimms; Dimm Identification - HP ProLiant WS460c G6 Workstation Blade User Manual

Channel
3
This multi-channel architecture provides enhanced performance in Advanced ECC mode. This architecture
also enables the Mirrored Memory and Lockstep memory modes. This workstation blade supports both
Registered PC3 DIMMs (RDIMMs) and Unbuffered DIMMs (UDIMMs).
DIMM slots in this server are identified by number and by letter. Letters identify the slots to populate for
specific AMP modes. Slot numbers are reported by ROM messages during boot and for error reporting.

Single-, dual-, and quad-rank DIMMs

To understand and configure memory protection modes properly, an understanding of single-, dual-, and
quad-rank DIMMs is helpful. Some DIMM configuration requirements are based on these classifications.
A single-rank DIMM has one set of memory chips that is accessed while writing to or reading from the
memory. A dual-rank DIMM is similar to having two single-rank DIMMs on the same module, with only
one rank accessible at a time. A quad-rank DIMM is, effectively, two dual-rank DIMMs on the same
module. Only one rank is accessible at a time. The workstation blade memory control subsystem selects
the proper rank within the DIMM when writing to or reading from the DIMM.
Dual- and quad-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, and a quad-rank DIMM would be 8-GB.

DIMM identification

IMPORTANT:
Attempting to mix these two types causes the server to halt during BIOS initialization.
The memory subsystem may be populated with either RDIMMs or UDIMMs, but mixing the two types is not
supported. To determine DIMM characteristics, use the label attached to the DIMM and the following
illustration and table.
Slot
F
C
This workstation blade does not support mixing RDIMMs and UDIMMs.
Slot number
5
6
Hardware options installation 26