The population rules for adding DIMMs to the server are as follows:
If your memory configuration uses only twelve DIMM slots, populate only the black DIMM slot (channel slot 0) within each memory channel
The Oracle Exadata Storage Server X7-2 uses a fixed base configuration of twelve 16 GB DDR4 DIMMs (192 GB). Do not attempt to install any other DIMM sizes in the server unless you are upgrading the memory with an Exadata memory expansion kit
If you are upgrading the memory to twelve 64 GB DDR4 DIMMs (768 GB), remove the existing 16 GB DIMMs and repopulate DIMM slots with 64 GB DIMMs
If you are upgrading the memory to twenty-four 64 GB DDR4 DIMMs (1.5 TB), remove the existing 16 GB DIMMs and repopulate all twenty-four DIMM slots with 64 GB DIMMs