How to best read RAM being used?

[briaboy]

Quick related question. I',m currently using 32GB (4x8GB). If I want to increase the memory, can I mix the GB amounts in the slots? e.g. keep 2x8GB and replace the other 2x8GB with 2x32GB?

Thanks!

[JFreak]

If other specs match, then yes. Problem is you need to be on the nerd side to make sure, so most are suggesting all of the sticks come from same batch.

[Darryl Ramm]

Originally Posted by briaboy

Quick related question. I',m currently using 32GB (4x8GB). If I want to increase the memory, can I mix the GB amounts in the slots? e.g. keep 2x8GB and replace the other 2x8GB with 2x32GB?

Thanks!

In future please don't spam unrelated questions onto other users threads.

You are better off with all DIMMs being the exact same size, manufacturer and exact part number. That dynamic memory works at all is a small miracle (look up "memory training" as an example). And DIMMs are not so expensive, so just do it right and make the most of the remaining life of this Intel Mac.

If the DIMMs are not all equal size then you want each memory channel to match the other in DIMM capacity/order. And all DIMMs meet the timing specs,but even better all be different capacity versions of the same DIMM part, or you know just buy four new identical DIMMs.

All this and more is clearly spelt out in Apple's very clear documentation about doing memory upgrades.

[Darryl Ramm]

Originally Posted by JFreak

If other specs match, then yes. Problem is you need to be on the nerd side to make sure, so most are suggesting all of the sticks come from same batch.

It's worse than just getting the right timing specs. Even if you get DIMMs from a reputable supplier and manufacturer and they claim some timing specs they still may not work, or may not work in a system with other DIMMs that also meet the same claimed timing specs. This is why motherboard OEMs spend so much time and effort qualifying DIMMs by exact model/part numbers not just by timing specs (and if you are in PC land, use those vendor qualified parts). In Mac land at least just go for all the same DIMMs, from vendors who sell to the Mac market == more chance if issues happen they will have seen them.

You often have no guarantee of if DIMMs or their components come from the same manufacturing "batch" (or what exactly that even means, DIMM manufacturing batch, DRAM chip batch, DIMM firmware version etc.) but you can look for exact part numbers and that tends to help make sure they are as identical as possible. Sometimes manufactures will have part numbers and revision numbers/codes. Even better to have all that match.

[briaboy]

As super-helpful - and as patronizing - as ever Darryl Ramm. Thank you.