Is all ddr4 so dimm ram the same?

Connectors Memory Connectors Memory Socket Connectors DIMM Connectors · Number DIMM Connectors DDR4 SODIMM 260P STD TE Connectivity Alcoswitch

This is because the slots that hold the individual RAM sticks are typically further away from the CPU than the SODIMM chips So while you can

ddr4 in ddr5 slot slot capacity) by electrically buffering the signals at a cost of an Module packaging edit A 16GB DDR4 SO-DIMM module by Micron DDR4 memory

ddr4 and ddr5 same slot Connectors Memory Connectors Memory Socket Connectors DIMM Connectors DIMM Connectors DDR4 SODIMM 260P STD TE Connectivity Alcoswitch