When targeting an FPGA that contains only 3 vertical banks within an I/O column, there are not enough I/O available to place a dual rank, dual slot 72-bit DDR4/3 DIMM.
However, the DDR4/3 IP tool currently does not limit this configuration.
After Generating Output Products, the following error is generated:
Later versions of Vivado will report this error:
Please only select a 64-bit dual rank, dual slot DIMM in FPGA devices where there are only 3 vertical banks within an I/O column.