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Single-, dual-, and quad-rank dimms, Dimm identification – HP ProLiant DL585 G7 Server User Manual

Page 46

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Hardware options installation 46

DR 1066 MHz

3

3 mixed

SR 1333 MHz
DR 1333 MHz

DR 1066 MHz

1066 MHz

800 MHz

3

1

2

SR 1333 MHz

DR 1333 MHz
DR 1066 MHz

QR 1066 MHz

800 MHz

667 MHz

o

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

NOTE:

There may be more than one memory bus speed menu option.

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.