Chosen Solution
Can I add RAM/Memory to my 2015 iMAC 21.5 model?
Sadly this model has soldered RAM and is not expandable.
The four orange outlined chips are the RAM chips. Here is the 2017 model which has both a socketed CPU and RAM
In any case you might find upgrading your drive to a faster model (SATA) and if your system has a PCIe slot then you could also install a larger Blade SSD (the line of solder pads just to the right of the Ethernet RJ45 connector is where it would be).
