Which banks/DIMMs for different size DIMMs for 2017 27 in iMac

[DerKommissar]

Hey- I've got my original 2x4 GB sticks and new 2x16 GB DIMMs installed in my 2017 27 in iMac for a total of 40 GB of ram, but I'm not sure I have them in the right slots to enable dual channel memory. Currently they are arranged like this...

Bank 0/DIMM0: 4 gb
Bank 0/DIMM1: 16 gb
Bank 1/DIMM0: 4 gb
Bank 1/DIMM1: 16 gb

That seems wrong to me, but I think I had trouble booting in any other configuration.

Thanks for the help!

 

[DeltaMac]

If you have different pairs to install, identical pairs go in slots 1-3, and 2-4.
So, you are correct.

 

[DerKommissar]

Thanks! I appreciate it!