HP ProLiant DL580 Gen8 Server - Manual (Page 50)

Hardware options installation 50
Advanced Memory Protection options are configured in 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
"HP ROM-Based Setup Utility."
The server can operate in independent channel mode (performance) or combined channel mode (lockstep).
Lockstep mode improves the system reliability and availability. If running with RDIMM (built with x4 DRAM
devices), the system can survive the complete failure of two DRAM devices (DDDC). Running in independent
mode, the server can only survive the complete failure of a single DRAM device (SDDC).
Maximum capacity
DIMM type DIMM rank One processor Two processors Four processors
RDIMM Single-rank (4GB) 96 GB 192 GB 384 GB
RDIMM
Single-rank (8 GB) 192 GB 384 GB 768 GB
RDIMM Dual-rank (16 GB) 384 GB 768 GB 1.5 TB
LRDIMM Quad-rank (32 GB) 768 GB 1.5 TB 3 TB
For the latest memory configuration information, see the QuickSpecs on the HP website
( http://www.hp.com/go/productbulletin ).
Advanced ECC memory configuration
Advanced ECC memory is the default memory protection mode for this server. Standard ECC can detect and
correct single-bit memory errors and only detect multi-bit memory errors. When multi-bit errors are detected
using Standard ECC, the error is signaled to the server to halt the server.
Advanced ECC protects the server against some multi-bit memory errors. Advanced ECC can detect and
correct up to 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:
• Install DIMMs only if the corresponding processor is installed.
• When multiple processors are installed, HP recommends balancing the DIMMs across the all
processors.
• White DIMM slots denote the first slot of a channel (Ch 4A, Ch 9B, Ch 1C, Ch 12D...).