Best practices for memory allocation and configuration include:
- Do not overcommit memory when sizing because memory is often not the constraining resource. Overcommitting memory increases the possibility of performance degradation if contention for memory resources, such as swapping and ballooning of memory, occurs. Overcommitted memory can also affect storage performance when swap files are created.
- Populate memory in units of six DIMMs per CPU to yield the highest performance. Dell EMC PowerEdge servers using 2nd Generation Intel Xeon Scalable processors have six memory channels per CPU, which are controlled by two internal memory controllers, each handling three memory channels. To ensure that your environment has the optimal memory configuration, use a balanced configuration, where each CPU supports a maximum of 12 DIMMs (or 24 DIMMs for a dual-CPU server). The most effective configuration is 12 DIMMs (6 per processor) with Intel Xeon Scalable processors.