Advanced Ecc Memory Population Guidelines; Double Device Data Correction - HP ProLiant BL620c G7 User Manual

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Online Spare memory mode provides protection against persistent DRAM failure. Rank-sparing is more
efficient than DIMM-sparing since only a portion of a DIMM is set aside for memory protection. For
more information, see "Online Spare memory population guidelines (on page 45)."
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Mirrored Memory mode provides the maximum protection against failed DIMMs. Uncorrectable errors
in the DIMMs of one memory controller are corrected by the DIMMs in the mirrored memory controller.
The two memory controllers of each processor form a mirrored pair. For more information, see
"Mirrored Memory population guidelines (on page 46)."
AMP modes 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 68)."
For the latest memory configuration information, see the QuickSpecs on the HP website
(http://www.hp.com/go/ProLiant).

Advanced ECC memory population guidelines

Advanced ECC memory is the default memory protection mode for the server, with the following limits:
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On server blades using Intel® Xeon® 6500 and 7500 series processors, up to 512 GB of active
memory using 16-GB DIMMs is supported in this AMP mode.
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On server blades using Intel Xeon E7 family processors, up to 1 TB of active memory using 32-GB
DIMMs is supported in this AMP mode.
Advanced ECC can correct single-bit and multi-bit memory errors on a single x8 or two adjacent x4 DRAM
devices.
The server provides notification when correctable error events have exceeded a pre-defined threshold rate.
When uncorrectable errors are detected using Advanced ECC, the server notifies the user and shuts down
the operating system.

Double Device Data Correction

The server blade is DDDC ready. The server blade will support this feature with a future planned firmware
upgrade. DDDC is supported only on systems that support Intel® Xeon® E7 family processors using x4
DIMMs only. For more information see the HP website (http://www.hp.com/go/bizsupport).
DDDC provides another layer of protection from memory errors, resulting in greater server up time. Unlike
memory mirroring, DIMM sparing, or RAID memory, DDDC does not require extra DIMMs. Therefore, DDDC
is a more efficient use of memory. DDDC can fix both single and double DRAM device memory hard errors.
DDDC works only with x4 DRAM devices. DDDC reserves one x4 DRAM device in each rank as a spare
device, ensuring data availability after hard failures within any two x4 DRAM devices.
The system must be in Advanced ECC mode to use DDDC. DDDC is disabled in the following configurations:
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The memory configuration includes a mix of x4 and x8 DIMMs.
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Online Spare Memory is enabled.
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Memory Mirroring is enabled.
Hardware options installation 44