HP ProLiant BL490c G6 Server-Blade - Manual (Page 23)

Hardware options installation 23
The memory subsystem may be populated with either RDIMMs or UDIMMs, but mixing the two types is not
supported. To determine DIMM characteristics, use the label attached to the DIMM and the following
illustration and table.
Item Description Definition
1 Size —
2
Rank 1R = Single-rank
2R = Dual-rank
4R = Quad-rank
3 Data width x4 = 4-bit
x8 = 8-bit
4 Memory speed 10600 = 1333-MHz
8500 = 1066-MHz
5
DIMM type R = RDIMM (registered)
E = UDIMM (unbuffered with ECC)
For the latest supported memory information, see the QuickSpecs on the HP website ( http://www.hp.com ).
Memory configurations
To optimize server blade availability, the server blade supports the following AMP modes:
• Advanced ECC—provides the greatest memory capacity for a given DIMM size, while providing up to
4-bit error correction. This mode is the default option for this server blade.
• 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 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 49 )."