Memory Upgrade

I am going to be a bit blunt and if I sound offensive, please don't take it as such.

In short, you have the wrong machine to do the type of work you want to do. Your 21.5" iMac was a base model iMac and was designed to only do very basic computing, meaning getting e-mail and basic Internet surfing. It was never designed to handle professionial grade apps like most of the Adobe suite of products. As you have learned upgrading the RAM is not simple and can be very expensive as it requires a complete disaassmbley of the computer and many AASPs refuse to do the work.

My advice is to sell the computer and buy a Mac with a minimum of 16GB of RAM and the largest SSD you can afford.

Sorry, I know this is the last thing you wanted to read however I think in the end this is what you will need to do.

Best of luck!

Welcome to the Apple Support Communities.

Please let us know the year and screen size of your iMac, and why you want more RAM/Memory.

Jack

What model ID and year is your iMac?

An Apple Authorized Service Provider may be able to help, but not an Apple Store. Here is what Apple says:

Memory is not removable by users on iMac (21.5-inch, Late 2012), iMac (21.5-inch, Late 2013), iMac (21.5-inch, Mid 2014), iMac (21.5-inch, 2017), iMac (Retina 4K, 21.5-inch, 2017), and iMac (Retina 4K, 21.5-inch, 2019). If the memory in one of these computers needs repair service, contact an Apple Retail Store or Apple Authorized Service Provider. If you’d like to upgrade the memory in one of these models, an Apple Authorized Service Provider can help. Before you schedule an appointment, confirm that the specific Apple Authorized Service Provider offers memory upgrade services.

Find an AASP here: Get Support.

Jack