Hardware options installation 33
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Advanced ECC—Provides up to 4-bit error correction and enhanced performance over Lockstep mode.
This mode is the default option for this server.
•
Online spare memory—Provides protection against failing or degraded DIMMs. Certain memory is
reserved as spare, and automatic failover to spare memory occurs when the system detects a DIMM that
is degrading. This allows DIMMs that have a higher probability of receiving an uncorrectable memory
error (which would result in system downtime) to be removed from operation.
Advanced Memory Protection options are configured in the BIOS/Platform Configuration (RBSU). If the
requested AMP mode is not supported by the installed DIMM configuration, the server boots in Advanced
ECC mode. For more information, see the
HP UEFI System Utilities User Guide for HP ProLiant Gen9 Servers
on the HP website Maximum capacity
DIMM type
DIMM rank
One processor
Two processors
RDIMM
Single-rank (8 GB)
64 GB
128 GB
RDIMM
Dual-rank (16 GB)
128 GB
256 GB
LRDIMM
Quad-rank (32 GB)
256 GB
512 GB
For the latest memory configuration information, see the QuickSpecs on the HP website
Advanced ECC memory configuration
Advanced ECC memory is the default memory protection mode for this server. Standard ECC can correct
single-bit memory errors and detect multi-bit memory errors. When multi-bit errors are detected using
Standard ECC, the error is signaled to the server and causes the server to halt.
Advanced ECC protects the server against some multi-bit memory errors. Advanced ECC can correct both
single-bit memory errors and 4-bit memory errors if all failed bits are on the same DRAM device on the DIMM.
Advanced ECC provides additional protection over Standard ECC because it is possible to correct certain
memory errors that would otherwise be uncorrected and result in a server failure. Using HP Advanced
Memory Error Detection technology, the server provides notification when a DIMM is degrading and has a
higher probability of uncorrectable memory error.
Online Spare memory configuration
Online spare memory provides protection against degraded DIMMs by reducing the likelihood of
uncorrected memory errors. This protection is available without any operating system support.
Online spare memory protection dedicates one rank of each memory channel for use as spare memory. The
remaining ranks are available for OS and application use. If correctable memory errors occur at a rate
higher than a specific threshold on any of the non-spare ranks, the server automatically copies the memory
contents of the degraded rank to the online spare rank. The server then deactivates the failing rank and
automatically switches over to the online spare rank.
General DIMM slot population guidelines
Observe the following guidelines for all AMP modes:
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Install DIMMs only if the corresponding processor is installed.
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When two processors are installed, balance the DIMMs across the two processors.
