PHS-memory 16GB RAM memory for ASRock H170M Pro4S DDR4 UDIMM 2133MHz

This 16GB RAM is 100% compatible with the ASRock H170M Pro4S. What should you consider when upgrading RAM? The fast dual channel mode operation is optimally supported when the memory is installed in pairs. If you are using a Core i5 or Core i7 processor, you can only use UDIMM memory. If you are using a Xeon processor, you can use either ECC UDIMM memory or UDIMM memory without ECC. The ECC function is only supported if all installed memory modules are UDIMM ECC memory.