Preparing for additional memory
The specifications of memory that can be added to iMac (Retina 5K, 27-inch, 2017) are as follows.
PC4-2400 (19200) Unbuffered Nonparity 260-pin 2400MHz DDR4 SDRAM
Install memory in an iMac
Here, iRam’s memory 32GB (16GB x 2) was prepared.
Check memory capacity
Your Mac has four memory slots. Each slot can hold a 2400 MHz DDR4 memory module. 2 used memory slots, 2 empty slots