Dell EMC PowerEdge R240 Installation and Service Manual

The system supports Flexible Memory Configuration, enabling the system to be configured and run in any valid chipset architectural configuration. The following are the recommended guidelines for installing memory modules:

• All DIMMs must be DDR4.
• A maximum of two different ranked DIMMs can be populated in a channel regardless of rank count.
• If memory modules with different speeds are installed, they will operate at the speed of the slowest installed memory module(s).
• Populate memory module sockets only if a processor is installed.
  • For single-processor systems, sockets A1 to A4 are available.
  • In Optimizer Mode, the DRAM controllers operate independently in the 64-bit mode and provide optimized memory performance.

  Table 1. Memory population rulesThis table describes the memory population rules.

  Processor	Configuration	Memory population	Memory population information
  Single processor	Optimizer (Independent channel) population order	1, 2, 3, 4	Odd amount of DIMMs per processor allowed.

• Populate all the sockets with white release tabs first, followed by the black release tabs.
• When mixing memory modules with different capacities, populate the sockets with memory modules with the highest capacity first.
  NOTE:For example, if you want to mix 8 GB and 16 GB memory modules, populate 16 GB memory modules in the sockets with white release tabs and 8 GB memory modules in the sockets with black release tabs.
• Memory modules of different capacities can be mixed provided other memory population rules are followed.

• Mixing of more than two memory module capacities in one system is not supported.
• Unbalanced memory configurations will result in a performance loss so always populate memory channels identically with identical DIMMs for best performance.