HP PROLIANT ML330 G6 - Manual (Page 43)

Hardware options installation 43
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 2-GB single-rank DIMMs, a dual-rank DIMM would be 4-
GB, and a quad-rank DIMM would be 8-GB.
Memory configurations
To optimize server availability, the server supports the following AMP modes:
• Advanced ECC—provides the greatest memory capacity for a given DIMM size, while providing up
to 8-bit error correction, depending on the specific DIMM type. This mode is the default option for
this server.
• Mirrored Memory—provides maximum protection against failed DIMMs. Uncorrectable errors in one
channel are corrected by the mirror channel.
• Lockstep—provides enhanced protection while making 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.
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 76 )."
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 Processor
Single-rank 72 GB
Dual-rank 72 GB
Quad-rank 48 GB
UDIMM maximum memory configurations
The server supports a maximum of 12 GB 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.