Chosen Solution
Hello i just purchassed a set of 2x 32GB Ram, i have installed the ram on the mac but in the mac info tab it’s only showing 32GB and only one memory slot used the other one is empty do you have any idee how to fix this ?
here’s the the ram i’m using : https://www.amazon.com/DATARAM-2666MHz-P…
While this is a pain to do, you’ll need to remove one of the SO-DIMM’s to see if you can isolate out which SO-DIMM is not working. Then take the working SO-DIMM placing it into the other slot and then test again. Either one of the SO-DIMM’s is bad or one of your sockets is bad.
Does anyone know which how the slots on the board ( A and B) correspond to the slots displayed in the GUI (1 and 2)? I am having the same issue and already swapped once, slot on the left of GUI remains “Empty”.
UPDATED GUI left slot = BANK 0/ChannelA-DIMM0 on my machine.
I had the same problem (didn’t recognize one of the aftermarket [Samsung] RAM cards) and tried ‘reinstalling’ the cards with no luck. As a last effort I tried doing the diagnostic (holding D at startup) which reported no problems - but when it booted up it recognized the other card!! (it’s at least easier than taking the machine apart again; and also may just be a good idea to do any time you install new RAM to force the machine to recognize it?)
