HP ProLiant BL660c Gen8 Server Blade - Manual (Page 37)

Hardware options installation 37
Online Spare memory configuration
Online spare memory provides protection against degraded DIMMs by reducing the likelihood of
uncorrected memory errors. This protection is available without any operating system support.
Online spare memory protection dedicates one rank of each memory channel for use as spare memory. The
remaining ranks are available for OS and application use. If correctable memory errors occur at a rate
higher than a specific threshold on any of the non-spare ranks, the server blade automatically copies the
memory contents of the degraded rank to the online spare rank. The server blade then deactivates the failing
rank and automatically switches over to the online spare rank.
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.
General DIMM slot population guidelines
Observe the following guidelines for all AMP modes:
• Install DIMMs only if the corresponding processor is installed.
• Balance the DIMMs across the installed processors.
• White DIMM slots denote the first slot of a channel (Ch 1-A, Ch 2-B, Ch 3-C, Ch 4-D).
• Do not mix RDIMMs and LRDIMMs.
• When two processors are installed, install the DIMMs in sequential alphabetic order balanced between
the two processors: P1-A, P2-A, P1-B, P2-B, P1-C, P2-C, and so forth.
• When four processors are installed, install the DIMMs in sequential alphabetic order balanced across
the four processors: P1-A, P2-A, P3-A, P4-A, P1-B, P2-B, P3-B, P4-B, P1-C, and so forth.
• For DIMM spare replacement, install the DIMMs per slot number as instructed by the system software.
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 for server models with Sandy Bridge processors are supported as indicated in the following
table.
Populated slots
(per channel)
Rank Speeds supported
(MT/s)
1, 2
Single- or dual-rank 1333, 1600
1, 2 Quad-rank 1333
DIMM speeds for server models with Ivy Bridge (v2) processors are supported as indicated in the following
table.
Populated slots
(per channel)
Rank Speeds supported
(MT/s)
1, 2
Single- or dual-rank 1600, 1866
1, 2 Quad-rank 1866