Intel S5000PAL manual Memory Sparing and Mirroring, Four Dimm Configuration Example

DIMM A1 Socket

DIMM B1 Socket

DIMM C1 Socket

DIMM D1 Socket

TP02327

Figure 8. Four DIMM Configuration Example

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 (FBD) with DDR2 DRAM technology.

•Use only FBD DDR2-533 and FBD DDR2-667 stacked DIMM modules.

In determining your memory requirements, the need for memory sparing or memory mirroring must be considered. For a complete list of supported memory DIMMs, see the links under "Additional Information and Software."

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.

12 Intel® Server Board S5000PAL User’s Guide