Dell PowerEdge XR8620t Installation and Service Manual

The following are the recommended guidelines for installing memory modules:

• All DIMMs must be DDR5.
• If memory modules with different speeds are installed, they operate at the speed of the slowest installed memory module(s).
• Populate memory module sockets only if a processor is installed.
• In Optimizer Mode, the DRAM controllers operate independently in the 64-bit mode and provide optimized memory performance.

  Table 1. Memory population rulesThe below table describes the memory population information.

  Processor	Memory population	Memory population information
  Single processor	A{1}, A{2}, A{3}, A{4}, A{5}, A{6}, A{7}, A{8}	8 DIMMs are supported per system.

• Not more than two DIMM part numbers allowed in the system.
• x4 and x8 DRAM based memory modules can be mixed.
• For best performance, populate all memory channels equally (8DIMMs per CPU) using identical DIMMs.
• Supported total number of RDIMMs in system: 2DIMMs, 4DIMMs, 6DIMMs, 8DIMMs.
• 3 DIMMs, 5 DIMMs, 7DIMMs configurations are not supported.
• Population order requires the largest capacity DIMM be placed first. For example, if we are populating with 32GB and 64GB RDIMMs, we would populate 64GB RDIMMs first.