Dimm Ranks; Dimm Handling Guidelines; Dimm Installation Guidelines; Installing A Dimm - HPE ProLiant MicroServer Gen10 User Manual

DIMM ranks

To understand and configure memory protection modes properly, an understanding of DIMM rank 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 8 GB single-rank DIMMs, a dual-rank DIMM would be 16 GB, and a
quad-rank DIMM would be 32 GB, and an octal-rank LRDIMM would be 64 GB.
LRDIMMs are labeled as quad- and octal-rank DIMMs. There are four and eight ranks of DRAM on the DIMM,
but the LRDIMM buffer creates an abstraction that allows the DIMM to appear as a logical dual-rank DIMM to
the system. This is called Rank Multiplication. The LRDIMM buffer also isolates the electrical loading of the
DRAM from the system to allow for faster operation. These two changes allow the system to support up to
three LRDIMMs per memory channel, providing for greater memory capacity and higher memory operating
speed compared to quad-rank RDIMMs.

DIMM handling guidelines

When handling a DIMM, observe the following guidelines.
• Avoid electrostatic discharge.
• Always hold DIMMs by the side edges only.
• Avoid touching the connectors on the bottom of the DIMM.
• Never wrap your fingers around a DIMM.
• Avoid touching the components on the sides of the DIMM.
• Never bend or flex the DIMM.
CAUTION:
Failure to properly handle DIMMs can cause damage to the components on the DIMM, as well as the
system board connector.

DIMM installation guidelines

When installing a DIMM, observe the following guidelines.
• Before seating the DIMM, open the DIMM slot and align the DIMM with the slot.
• To align and seat the DIMM, use two fingers to hold the DIMM along the side edges.
• To seat the DIMM, use two fingers to apply gentle pressure along the top of the DIMM.
For more information, see the Hewlett Packard Enterprise website.

Installing a DIMM

About this task
The server uses memory to perform almost all of its operations. Upgrading the server memory capacity leads
to faster boot-up, processing period, and timely responses to promote optimum system performance.
Procedure
1. Power down the server on page 22.
2. Disconnect the power cord from the AC source, and then from the server.
46 DIMM ranks