IMac A2115 Class: DDR4. Ram Class: DDR4. Kit Capacity: 128GB. Capacity: 32GB. Apple iMac PRO models require the use of ECC RDIMM modules. SubFamily: 2020 / 5K. Your computer loads a program or file you select from the hard drive in to your computers RAM, then it will access each bit of data from there.
eBay