DDR4 16GB modules can be built as 1Rx8 with 16Gb DRAMs or 2Rx8 with 8Gb DRAMs, whereas DDR5 16GB modules can
only be built as 1Rx8 with 16Gb DRAMs. Because rank and configuration can make a big difference under benchmark
conditions, the only fair comparison of DDR4 and DDR5 would be between the same module type and configuration (i.e. 8GB 1Rx16 or 16GB 1Rx8).