Best practices for memory allocation and configuration include:
- Because memory is often not the constraining resource, do not overcommit memory when sizing. 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 eight per CPU to yield the highest performance. Dell PowerEdge servers using 4th generation Intel Xeon Scalable processors have eight memory channels per CPU. Four internal memory controllers control the CPUs, each handling two memory channels. To ensure that your environment has the optimal memory configuration, use a balanced configuration. Each CPU should support a maximum of 12 DIMMs (or 64 DIMMs for a four-CPU socket server). The most effective configuration is 32 DIMMs (eight per processor) with 4th generation Intel Xeon Scalable processors on four CPU socket servers.