Hardware options installation  57 
Memory configurations 
To optimize server availability, the server supports the following AMP modes: 
•  Advanced ECC—Provides up to 4-bit error correction and enhanced performance over Lockstep mode. 
This mode is the default option for this server. 
•  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. This feature enables DIMMs that have a higher probability of receiving an uncorrectable 
memory error (which would result in system downtime) to be removed from operation. 
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 117)." 
The server also can operate in independent channel mode or combined channel mode (lockstep). When 
running in lockstep mode, you gain reliability in one of two ways: 
•  If running with UDIMMs (built with x8 DRAM devices), the system can survive a complete DRAM failure 
(SDDC). In independent channel mode, this failure would be an uncorrectable error. 
•  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 
RDIMM 
RDIMM 
Dual-rank  2 GB  8 GB 
For the latest memory configuration information, see the QuickSpecs on the HP website 
(http://www.hp.com). 
 
General DIMM slot population guidelines 
Observe the following guidelines for all AMP modes: 
•  Install DIMMs only if the corresponding processor is installed. 
•  When two processors are installed, balance the DIMMs across the two processors. 
•  White DIMM slots denote the first slot of a channel (Ch 1-A, Ch 2-B, Ch 3-C). 
•  Do not mix UDIMMs or RDIMMs. 
•  When two processors are installed, install the DIMMs in sequential alphabetical order balanced 
between the two processors: P1-A, P2-A, P1-B, P2-B, P1-C, P2-C, and so on. 
For detailed memory configuration rules and guidelines, use the Online DDR3 Memory Configuration Tool 
on the HP website (http://www.hp.com/go/ddr3memory-configurator). 
DIMM speeds are supported as indicated in the following table. 
 
Populated slots 
(per channel) 
Rank  Speeds supported (MT/s) 
1 
Single or dual rank  1333, 1600