Mac RAM Upgrade Guide

iMac RAM upgrades are easy for most models, and it’s a good idea to do it yourself, for two reasons: firstly you’ll get to know your iMac better, and secondly it’s possible to save a few hundred bucks rather than having Apple do the expensive upgrade. There are a few situations, though, where you might need to contact Apple or an Apple authorized service provider to install the RAM. Memory isn’t removable by users on every 21.5-inch iMac since the late 2012 model despite it being possible to do on 27-inch models. In these cases, sadly you will need to pay higher prices to get the upgrade you want.

How to upgrade iMac RAM

Upgrading your iMac with more RAM is super-easy and requires only a few steps. The first and most obvious task is to identify your iMac to know which memory it is that you will need to purchase. The price of the memory module will differ based on the iMac model you own.

Apple has guidelines for the maximum amount of RAM each iMac model supports, but upgrade specialists say the devices are capable of supporting more.

Until 2007, early models of the iMac had just two memory slots. Since then, Apple decided to implement four slots, which is still the case today. However, we highly recommend checking the type of RAM you need to buy, otherwise the iMac won’t recognize it.

What RAM should I buy?

Memory modules evolve over time, and often a new iMac will use a more advanced module. Here we’ve compiled a guideline for the type of RAM you should be looking to buy, depending on your model of iMac:

Any 27-inch iMac models with upgradable RAM manufactured between late 2012 and mid 2015 come with a base memory of 8GB and support a maximum of 32GB. Importantly, you need to make sure the memory you’re using is 204-pin 1600MHz DDR3 SDRAM. Late 2015 iMacs have the same maximum memory specifications as previous versions (8GB to 32GB) but utilizes 1867HMz DDR3 SDRAM instead.

The mid 2017 iMacs gave users the ability to boost the maximum RAM from 8GB to 64GB by filling all four slots with 16GB modules. It’s important to note that mid 2017 models use 260-pin 2400MHz DDR SDRAM. Early 2019 models also go from 8GB to 64GB, but they instead require 260-pin 2666MHz DDR4 SDRAM modules.

Apple doubled the maximum memory for its mid 2020 model, allowing users to go to 128GB by adding four 32GB modules. However, the modules are the same as the early 2019 models: 260-pin 2666MHz DDR SDRAM.

How to install the RAM

Once you’ve figured out which memory types are compatible with your iMac, installing the RAM is easy. It only requires a few minutes, but there is still a slight difference between some models since Apple migrated from one design to another. Essentially the one thing you’ll need for all models is a soft, clean towel or cloth that you’ll place on the desk or other flat surface to protect the display from getting scratched.

The installation of the memory is pretty straightforward: first, you need to locate the memory compartment. On models released between 2006 and 2011 this is located at the bottom. The memory access door is secured by three screws on these earlier models.

On models released after 2012, this compartment is located on the back of the iMac above the AC power port. Apple made access easier, and the memory compartment opens with a button. A full step-by-step guide on how to install iMac RAM on various models is available on Apple’s support page.

One last thing that you should be careful with when upgrading your iMac’s memory is the compatibility between each of the individual components. Computer operating systems handle memory in very specific ways, so after finding the right type of RAM for your iMac with the guidelines above you should then try to ensure that you upgrade your system with matching memory.

Why not Apple RAM

It’s good to have the maximum amount of RAM in your iMac at the moment of purchase, since this is a good way to expand its lifespan. But if you didn’t opt for the maximum RAM, then that’s no problem because you can upgrade it at any time. And you won’t break the bank, either. In fact, this is the main reason why we don’t recommend maxing out RAM at the moment of purchase of an iMac with upgradeable memory. For example, the mid 2020 21.5-inch 4K iMac comes with 8GB of RAM. But if you want to upgrade to 16GB it will cost you an additional $200, while 32GB of 2400MHz DDR4 RAM (the maximum supported) adds another $600. By comparison, a similar non-Apple 32GB DDR4 2400MHz kit costs $250 on Amazon.

In other words, while a factory upgrade is nice as you won’t have to worry about performance for the next ten years or so, it does come at a cost. Opting for a third-party RAM upgrade will save a significant amount of cash, and considering how easy upgrading is this is definitely something worth doing.

Best RAM brands for Mac

With so much choice available when it comes to system memory, it can be a challenge just to pick the one that is right for you. As such, we’ve picked three brands that we think you should consider when looking to upgrade your Mac’s memory.

Video guide and instructions

If a picture is worth a thousand words, then how much is a video worth? But would you prefer written guidance or a step-by-step video on how to install memory into your iMac? OWC’s online store, MacSales.com, is the best option for easy-to-follow video guides. Here you’ll find detailed videos on how to install memory and SSDs into your iMac and various other Mac products. These video guides deliver just the right amount of information that you won’t find on Apple’s iMac RAM upgrade support page.

Of course, if you have already done a few RAM upgrades then the steps should be familiar, but those upgrading their iMac for the first-time should definitely watch the tutorial videos to get an overview of the complete process from beginning to end.