iMac (late 2015): Is this RAM arrangement OK?

[hzxu]

I bought 2x8GB RAM sticks for my late 2015 iMac that came with 2x4GB sticks of RAM, I put it in but the machine doesn't boot, I searched and found the RAM sticks have to be inserted in certain order, so it now ends up like this:

I read from somewhere that the RAM sticks have better performance if installed in pair, ie. BANK 0 should have a pair of 8GB sticks and BANK 1 should have a pair of 4GBs, so I wonder if this is the case, then I'll try to make them in pairs.

Thanks!

 

[DeltaMac]

Looking at the RAM sticks in the slots, you should see either 4,8,4,8 or 8,4,8,4

The configuration that you show in your graphic should be one of those sets, and should give you best performance.
You should be OK with the setup that you show in your graphic.

 

[wilberforce]

I bought 2x8GB RAM sticks for my late 2015 iMac that came with 2x4GB sticks of RAM, I put it in but the machine doesn't boot, I searched and found the RAM sticks have to be inserted in certain order, so it now ends up like this:

View attachment 1862622
I read from somewhere that the RAM sticks have better performance if installed in pair, ie. BANK 0 should have a pair of 8GB sticks and BANK 1 should have a pair of 4GBs, so I wonder if this is the case, then I'll try to make them in pairs.

Thanks!

Looks perfect, as you have the same amount of RAM in BANK 0 as BANK 1. (Bank is also known as channel)

 

[hzxu]

Thanks guys!