Upgrade iMac Memory

[brenicor87]

Hi. I'm looking to upgrade the memory in my iMac. I have a Retina 5K, 27-inch, 2017 with 16BG. And I was thinking of adding OWC 32GB (2 x 16GB) of compatible RAM. While conducting research, on Amazon, the top comment talks about how it is not compatible with stock Apple RAM, and that with purchasing this RAM I would need to replace what I already have, NOT add to it.

My questions are: is this true? And if so, what RAM I could buy to ADD to what I already have and not replace it. Is what's listed on the Apple store my only option?

Thanks!

 

[Richdmoore]

I ran with stock apple ram and crucial ram at the same time, with an 27" iMac 2017. I had no problems.

I used these: https://www.amazon.com/gp/product/B072K5NPRM

 

[BATman.Berlin]

I have two bars of PNY added to the existing pre installed without any issues. Just have the existing occupy slot 1 and 3 and the new 2 and 4 and you will be fine

 

[Migranya]

If you have modules that work at different speeds, the best will automatically try to mimic the worst, and this can cause occasional problems.

 

[Fishrrman]

Here's the source I use for RAM. Never had a problem:
iMac Memory Upgrades

 

[brenicor87]

Thank you so much for all of the help! Saved me hundreds of dollars!