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Whitepaper – Balanced Memory with 2nd Generation Intel® Xeon Scalable Processors
© 2019 Dell Inc. or its subsidiaries.
Internal Use - Confidential
4. Guidelines for Balancing Memory
4.1 Overview
To ensure effective interleaving is created, memory must be populated into a balanced
configuration. Variables such as DIMM consistency and slot population will dictate
whether a configuration is balanced or unbalanced. At both the socket and server level,
memory bandwidth is optimized when the guidelines below are implemented:
1. All memory modules inside the memory subsystem are identical
• They must have the same size, speed, rank count and DIMM type
2. All populated memory channels are identical and maximized
• Channels must be fully populated with one or two DIMMs
3. All server sockets should have identical memory subsystems
4.2 Identical Memory Modules
All memory modules being used must be the same. This means that the DIMM size (or
capacity), speed, rank count and type should be consistent. For example, if all the
memory modules connected to the CPU channels are 32Gb, 2133MT/s, RDIMMs with
two ranks, then the configuration is following this guideline. Figure 3 demonstrates
what happens when two different DIMMs are populated to the same CPU:
Figure 3: Two unique interleave sets were created because two unique DIMM sizes were populated