Hi I have tried every combination possible and any thing over the original 64 gb I had in the machine will not work I have tock out my old ram replaced it with 64 gb of new ram and it works but when you go over 64 gb it stopes. my machine is 6core chips 3.46
GHZ5.1 Mac Pro desktop
You still didn’t tell us the spec of your DIMM, “old 64GB”, “new 64GB” means nothing here. Are they all RDIMM / UDIMM? What’s their latency? What’s their memory rank?...
If your new DIMM spec doesn’t match the old DIMM, there is a chance that you can’t boot with all of them installed.