HP DL380 G7 - Manual (Page 48)

Hardware options installation 48
• Lockstep—provides enhanced protection over Advanced ECC mode while continuing to make all
installed memory available to the operating system. The server can continue to function if a single- or
mulit-bit memory failure within a single DRAM device occurs.
• 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 and receiving a high rate of correctable memory errors. 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.
• Mirrored Memory—provides maximum protection against failed DIMMs. Uncorrectable errors in one
channel are corrected by the mirror channel.
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 (on page 72 )."
For the latest memory configuration information, see the QuickSpecs on the HP website
( http://www.hp.com ).
RDIMM maximum memory configurations
The following table lists the maximum memory configuration possible with 8-GB RDIMMs.
Rank Single-processor Dual-processor
Single-rank 72 GB 144 GB
Dual-rank 72 GB 144 GB
Quad-rank
48 GB 96 GB
UDIMM maximum memory configurations
The server supports a maximum of 12 GB with one processor and 24 GB with two processors using 2-GB
single- or dual-rank UDIMMs.
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. The server provides
notification that correctable error events have exceeded a pre-defined threshold rate.
Lockstep memory configuration
Lockstep mode provides protection against multi-bit memory errors that occur on the same DRAM device.
Lockstep mode can correct any single DRAM device failure on x4 and x8 DIMM types. The DIMMs in each
channel must have identical HP part numbers.