MacPro RAM and mixing capacities

I’m about to buy a new Mac Pro, just wondering do I need to remove the ram that comes with it and replace if I get ram from OWC or can I use both?

Originally considered getting from Apple, factory install etc…
However, price diff was huge, so went w OWC, easy to install.

That’s what I’m gonna go with, my question is more about using OWC ram in conjunction with the factory installed ram or if I need to remove the factory ram first. (effectively replacing it)

You can absolutely mix. You just need to make sure that you handle mismatched RAM sizes correctly based on Apple’s guides. For example, if you buy 128GB of RAM from OWC, you can put a 32GB DIMM in the first pair of each slot, and then the original 8GB in the second slot of each pair, and so on.

That’s great to know! Do you have a link where I can find the guide or more guidance?

1 Like

Read this page…

Look for the section on Installing R-DIMMs of mixed capacities. When you are done it could look like this…I have this configuration in both a 16core and a 28core Mac Pro.

Most forget you can do this, and instead mistake the fact that you shouldn’t mix RAM clock speeds with RAM capacities.

It’s a little complicated. If you are going to mix, you need to make sure you get RDIMM’s, which OWC does have. They will also buy the Apple chips from you if you just want to have all the same. (Though, as a former Apple tech support phone rep, it was totally normal to tell someone that I couldn’t help them with some major system problem until they removed all the third-party memory out of their computer and had only Apple original chips in there, so maybe you want to keep the Apple memory to be safe)

Here is Apple’s stereo-instruction-language guide: