HP BL2X220C - Manual (Page 25)

Hardware options installation 25
• Lockstep—provides enhanced protection while making all installed memory available to the
operating system. The server blade can continue to function if a single- or multi-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 blade boots in Advanced ECC mode. For more
information, see "HP ROM-Based Setup Utility (on page 34 )."
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 16-GB RDIMMs.
Rank Maximum memory configuration
Single-rank 96 GB
Dual-rank 96 GB
Quad-rank 64 GB
UDIMM maximum memory configurations
The server blade supports a maximum of 24 GB of memory with one processor and 48 GB of memory
with two processors using 4-GB dual-rank UDIMMs.
Advanced ECC memory configuration
Advanced ECC memory is the default memory protection mode for this server blade. 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 blade and causes the server blade to halt.
Advanced ECC protects the server blade 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 blade failure. The server blade
provides notification that correctable error events have exceeded a pre-defined threshold rate.
General DIMM slot population guidelines
Observe the following guidelines for all AMP modes:
• Always populate channels 1 and 2 for both processors.
• To maximize performance, distribute the total memory capacity between both processors in a server
as evenly as possible.
• Do not mix Unbuffered and Registered PC3 DIMMs.
DIMM speeds are supported as indicated in the following table.
Rank Speeds supported (MHz)
Single- or dual-rank 1333, 1066