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Mix memory sizes with E5530 Xeon Processor

Community Manager

We are looking to purchase some dell servers with the E5530 Xeon Processor and Intel 5520 chipset. We are being told that we cannot mix 4gb and 8gb memory modules beacuse the processor does not support it? Does anyone have any info on using this configuration.

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Community Manager

Hi there,

See the requirement for an Intel Server Board like S5520UR for example:

It says clearly that mixing memory with different sizes, type, speed has not been tested, validated:

NoteThe following configurations are not validated, supported, or recommended:

  • Mixing of RDIMMs and UDIMMs
  • Mixing memory type, size, speed, and/or rank
  • Mixing memory vendors
  • Non-ECC memory

If someone else has tried this, may be they can help you or give you some more information.

All the best,




In addition to that,

Follow these rules for peak performance:

&# 149; Always populate both processors with equal amounts of memory to ensure a balanced

NUMA system.

&# 149; Always populate all 3 memory channels on each processor with equal memory capacity.

&# 149; Ensure an even number of ranks are populated per channel.

&# 149; Use dual-rank DIMMs whenever appropriate.

&# 149; For optimal 1333MHz performance, populate 6 dual-rank DIMMs (3 per processor).

&# 149; For optimal 1066MHz performance, populate 12 dual-rank DIMMs (6 per processor).

&# 149; For optimal 800MHz performance with high DIMM counts:

– On 12 DIMM platforms, populate 12 dual-rank or quad-rank DIMMs (6 ) per processor.

– On 16 DIMM platforms:

_ Populate 12 dual-rank or quad-rank DIMMs (6 per processor).

_ Populate 14 dual-rank DIMMs of one size and 2 dual-rank DIMMs of double the size

as described in the interleaving section.

&# 149; With the above rules, it is not possible to have a performance-optimized system with 4GB,

8GB, 16GB, or 128GB. With 3 memory channels and interleaving rules, customers need to configure systems with 6GB, 12GB, 18GB, 24GB, 48GB, 72GB, 96GB, etc., for optimized


Community Manager

"Ensure an even number of ranks are populated per channel."

What is the effect on performance if this isn't followed. eg

2X E5540

6X 1GB of single rack RAM?