I am looking to increase the RAM of my iMac (Retina 5K, 27-inch, Mid 2015). I found one on the Apple website, but it is $400. If I could find a better price, it would be amazing. I was looking around on Amazon, but don't know if the SDRAMs I found work with my iMac. Do you guys have any advise for how to tell whether or not the SDRAM is compatible with my iMac?

  • 1
    Can you provide the link on Apple's website where your found the product you are looking for? Apr 23, 2018 at 2:14

4 Answers 4


The official RAM specifications are given by Apple here: https://support.apple.com/en-us/HT201191

Using the list, you need to

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

  • PC3-12800
  • Unbuffered
  • Nonparity
  • 204-pin
  • 1600MHz DDR3 SDRAM

Note that only 32 GB of RAM is officially supported.

  • Am I able to have more then just 32 GB RAM? Will the Mac not accept more?
    – YusaMac205
    Apr 23, 2018 at 16:52
  • @YusaMac205 Looking at search results, people have reported instability when they attempted 64.
    – user71659
    Apr 23, 2018 at 17:40

http://www.crucial.com is a great website for checking RAM and other hardware compatibility. They also have a scanner tool (http://www.crucial.com/usa/en/systemscanner) to detect your computer type and give you a list of hardware that will work with your computer. Generally, they offer competitive prices.

Note: This is not promotional just trying to provide one of the best sites I have found. I am in no way affiliated with the website. The part about

Generally, they offer competitive prices.

is not promotional because the OP said

If I could find a better price, it would be amazing.

and therefore was looking for a "better price".

  • If those URLs change, this answer becomes useless, can you derive from those URLs information that can be used to answer the question, and provide them as supporting links? Apr 23, 2018 at 0:33
  • Yes, but, the site doesn't show how to figure out what SDRAMs are compatible with my iMac. It just shows some products they made that are compatible.
    – YusaMac205
    Apr 23, 2018 at 1:40
  • 7
    @MathieuK. Totally agree except for the fact that OP commented on how expensive Apple was selling it for. Do you still think I should remove it? Apr 23, 2018 at 4:58
  • @MathieuK. Ok. Well then it begs the question: If an OP asks a promotional question should you answer with a promotional answer? I will ask on Meta. Apr 23, 2018 at 22:25
  • 1
    Let us continue this discussion in chat.
    – Mathieu K.
    Apr 23, 2018 at 23:42

OWC and Macfixit specialise in Mac addons. You need to double check the model number is right, but have a look here:

https://eshop.macsales.com/shop/memory/iMac/Retina-5K/DDR3L https://www.macfixit.com.au/apple-memory-ram/imac/imac-27-5k-retina-display-ram-memory-2014/sort-by/position/sort-direction/asc/

Note: This is not promotional just trying to provide a site.


Your Mac intuitively already tells you what memory you should get to upgrade.

Start off by clicking on "About this Mac"

About this Mac

Then select the "Memory" tab. It will tell you how much is installed, which slots are available (if any) and what the memory specs are for your particular Mac.

About this Mac Memory

Click the "Memory Upgrade Instructions" link if you require more info.

As for memory, I use/recommend only trusted brands like the Crucial CT102464BF160B SODIMM. A lifetime warranty and excellent customer service is worth (IMO) the few extra coins.

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