Installing And Removing Memory Modules; Supported Memory; Memory Sparing And Mirroring - Intel MFS5000SI - Multi-Flex Server Compute Module User Manual

Installing and Removing Memory Modules

Supported Memory

The server board provides support for eight DDR2-667 fully-buffered DIMM sockets
across two branches. Each branch has two channels. Channel A consists of slots A1 and
A2; channel B consists of slots B1 and B2; channel C consists of slots C1 and C2; and
channel D consists of slots D1 and D2.
DIMMs must be populated in pairs across consecutive channels starting with the lowest
numbered slot in each channel. Slots A1 and B1 are paired, followed by slots C1 and D1.
For performance reasons, when configuring four DIMMs, DIMM pair A2 and B2 should
never be populated before DIMM pair C1 and D1. A four-DIMM configuration should be
populated as A1 and B1; C1 and D1.
In non-mirrored mode, all DIMMs with the same slot number within a given branch must
match (size, technology, manufacturer). It is not required to match DIMMs between
different slot numbers.
DIMMs must meet the following requirements:
•
Use only fully-buffered DIMMs (FB-DIMMs) with DDR2 DRAM technology.
•
Use only DDR2-667 stacked FB-DIMM modules.
In determining your memory requirements, the need for memory sparing or memory
mirroring must be considered.

Memory Sparing and Mirroring

The 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.
In a mirrored system, the maximum usable memory is one-half of the installed memory,
with a minimum of four DIMMs installed. Since the data is duplicated across DIMMs, it
means that up to one-half of the installed DIMMs are actively in use at any one time. The
remaining DIMMs are used for mirroring.
Memory mirroring and memory sparing are mutually exclusive. Only one can be active at
a time. See the Intel® Compute Module MFS5000SI Technical Product Specification for
additional information regarding the memory sub-system.
24 Intel® Compute Module MFS5000SI User Guide