Memory iMac (Retina 5K, 27", 2017)

A modest RAM upgrade like adding a pair of 4GB or 8GB modules, will allow you to open and run more app's at the same time. As mentioned, adding more will not dramatically increase the over-all performance of an iMac that has a slower internal HDD versus one that has an internal SSD.

For RAM modules, it is best to go with a trusted supplier like Crucial or OWC.

https://www.crucial.com/compatible-upgrade-for/apple/imac-(retina-5k--27-inch--2017)-imac18-3

https://eshop.macsales.com/shop/memory/imac-2017-27-inch

Hi there!

First, it's important to ask why you'd like to upgrade the memory. Is it due to performance issues? If so, adding memory may not help.

Let us know!

Jack