Question Which one is the better option - - - x4 ECC DDR4 RDIMM or x8 ECC DDR4 RDIMM ?

[MANOJKUNDU]

The width of memory chips x4 ECC DDR4 rdimm & x8 ECC DDR4 rdimm , which one is better in stability & performance wise.
Why Maximum DDR4 server Ram are made from x4 bit chips ? From which chips (x4 or x8 ) we can make maximum capacity memory modules.
Testing memtest in x4 bis ram or x8 bits ram have any difference. How customer can know modules are
made from which type of memory width (DQ lines of each memory chip)during memtest. Please guide me

 

[Misgar]

What server or workstation motherboard are you using? What is your CPU. How many DIMM slots per CPU?

How customer can know modules are
made from which type of memory width

Best bet is to check the motherboard manufacturer's QVL for compatible RAM.