Memtest failing on 5950x passing on 3300x

[bootstrapf7]

Hi, I have some G.Skill Ripjaws v 128GB ddr4 3200Mhz Cl16 memory 4 32GB sticks with a 5950x on a gigabyte aero g 570s motherboard.

A single stick fails in memtest86. The failing stick fails no matter the slot and working sticks pass in those slots.

I sent this back and the memory was replaced, sadly the replacement had a single stick that failed for a different reason.

The place I purchased it from AusPCMarket has run mem test on this returned memory and found no errors, however they are testing on a slower CPU Ryzen 3 3300x "ROG STRIX X570-I GAMING".

What I notice (see attachments below) we have some speed difference in caches and memory:
mine (1 stick): L3 36.8GB/s, Mem 21.8GB/s
mine (4 sticks) L3 43.5GB/s, Mem 40.5GB/s
Theirs (2 sticks): L3 27GB/s, Mem 17.8GB/s
(I didn't record speed for two sticks)

This time I believe they did run the memory at 3200Mhz although I don't know what cas latency they used.

I am wondering, is the Memtest they did reasonable in that the transfer speed is only 80% of what my machine can do with a single stick. Should I be pushing them to test such that they get similar memory bandwidth speeds, Perhaps witha better CPU or ensuring the case latencies are correct?

Could it be my motherboard or CPU? How would I diagnose that without additional memory or another DDR4 motherboard.

Thanks for your help,
 

-Luke

MemTest86-Report-20220113-095734.pdfMemTest86-Report-20220112-120850.pdf