HP ProLiant DL380 Gen9, User Manual

Page: 70 / 215

Hardware options installation 70
Mirrored memory configuration
Mirroring provides protection against uncorrected memory errors that would otherwise result in server
downtime. Mirroring is performed at the channel level to one memory channel pair that can be either:
•
Channel 1 data being mirrored in channel 2
•
Channel 3 data being mirrored in channel 4
If an uncorrectable error is detected in the active memory channel, data is retrieved from the mirror
channel. This channel becomes the new active channel, and the system disables the channel with the
failed DIMM.
General DIMM and NVDIMM-N slot population guidelines
Population requirements
•
Do not mix RDIMMs, UDIMMs, and LRDIMMs.
•
When NVDIMM-Ns are installed in this server, install at least one regular RDIMM in a DIMM slot
associated with the first processor installed.
•
Install DIMMs only if the corresponding processor is installed.
•
When mixing regular DIMMs and NVDIMM-Ns in a channel, install the regular DIMMs first and then
install the NVDIMM-Ns in the channel.
•
When installing NVDIMM-Ns in this server and using the HPE 96W Smart Storage Battery, install a
maximum of 16 NVDIMM-Ns in the server.
•
When single-rank, dual-rank, and quad-rank DIMMs are populated for two DIMMs per channel or
three DIMMs per channel, install the higher numbered rank DIMM first in the channel (starting from
the farthest DIMM slot). For example, install the quad-rank DIMM first, the dual-rank DIMM next, and
the single-rank DIMM last.
Population recommendations
•
To utilize all memory channels and provide best performance when one processor is installed, install
regular DIMMs in sequential alphabetic order: A, B, C, D, E, F, and so forth.
•
When two processors are installed, install the regular DIMMs in sequential alphabetic order
balanced between the two processors: P1-A, P2-A, P1-B, P2-B, P1-C, P2-C, and so forth. If
installing NVDIMM-Ns in an unbalanced configuration, see the HPE 8GB NVDIMM User Guide on
the Hewlett Packard Enterprise Information Library ( http://www.hpe.com/info/NVDIMM-docs ).
•
To achieve the best performance, install only two DIMMs per channel in servers with three DIMM
slots per channel. When three DIMMs per channel are populated, the speed reduces from 2400
MT/s or 2133 MT/s to 1600 MT/s.
The operating frequency is reduced to 1867 MT/s if the following are true:
o
If any channel in the system is populated with two DIMMs per channel and at least one of them is
NVDIMM.
o
If no channel in the system is configured with three DIMMs per channel.
o
If a channel in the system configured with two DIMMs per channel is populated with all regular
DIMMs, an NVDIMM-N installed in a one DIMM per channel configuration runs at 2133 MT/s.
For more information about server memory, see the Hewlett Packard Enterprise website
(
http://www.hpe.com/info/memory
).
Advanced ECC population guidelines
For Advanced ECC mode configurations, observe the following guidelines:
•
Observe the general DIMM slot population guidelines.