Single-, Dual-, And Quad-Rank Dimms; Dimm Identification - HP ProLiant DL585 G7 User Manual

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800 MHz—The memory bus speed is set to 800 MHz regardless of the quantity of memory modules
o
installed, unless the table above reflects a slower memory bus speed.
NOTE:

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 server 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

To determine DIMM characteristics, use the label attached to the DIMM and the following illustration and
table.
DR 1066 MHz
— 3 mixed SR 1333 MHz
DR 1333 MHz
DR 1066 MHz
1 2 SR 1333 MHz
DR 1333 MHz
DR 1066 MHz
QR 1066 MHz
There may be more than one memory bus speed menu option.
1066 MHz 800 MHz
800 MHz 667 MHz
Hardware options installation 46