Memory - Intel TIGI2U - Carrier Grade Server User Manual

Server Platform Features

Memory

The Server Board SE7520JR2 provides six DIMM sockets across two channels, Channel
A and Channel B. Channel A consists of DIMM sockets 1A, 2A, and 3A. Channel B
consists of DIMM sockets 1B, 2B, and 3B.
If six DIMMs are installed, the following maximum capacitites are possible:
For DDR-2 400: Maximum capacity of 16 GB

A minimum of one 256MB DIMM is required in DIMM socket 1A or 1B. This uses single-
channel interleave. However, for dual-channel interleave, providing optimum performance,
a minimum of two DIMMs should be installed in DIMM sockets 1A and 1B. Except for the
option of installing a single DIMM in socket 1A or 1B, DIMMs must be installed in pairs and
populated as follows:
DIMM1A and DIMM 1B: Populate these two sockets together first

DIMM 2A and DIMM 2B: Populate these sockets in addition to DIMM 1A and DIMM 2A

if four DIMMs are to be used.
DIMM 3A and DIMM3B: Populate these sockets after DIMM 1A, DIMM1B, DIMM2A,

and DIMM2B have been populated.
DIMMs must meet the following requirements:
Use only DDR2-400 ECC, registered DDR DIMM modules

Use only DIMMs that comply with the DDR specifications.

Use only DIMMs with DIMM organization of x72 ECC

Use only 240pin DIMMs


NOTE
When using DDR2-400 DIMM technologies, a maximum of four loads per memory channel
is supported. When all DIMMs used in the system match this technology, a maximum of
four DIMMs can be populated. Refer to the Intel
Product Specification for additional information regarding the memory sub-system.
In determining your memory requirements, the need for memory sparing or memory
mirroring must be considered.
Memory Sparing and Mirroring
The Intel® E7520 chipset includes hardware that supports memory mirroring and memory
on-line sparing. Both memory mirroring and memory on-line sparing provide a way to
prevent data loss in case a DIMM fails.
With memory mirroring the system maintains two copies of all data in the memory
subsystem. If a DIMM fails, the data is not lost because the second copy of the data is
available from the mirrored DIMM in the opposite channel. The system will not fail due to
memory error unless both the primary and the mirrored copy of the data become corrupt at
the same time.
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Intel Carrier Grade Server TIGI2U User Guide
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Server Board SE7520JR2 Technical
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