External RAM for Mac You can boost the performance of your Mac and prolong its life by adding more RAM. We explain which Macs can have their RAM updated, and show you how to upgrade RAM in the iMac, Mac mini, Mac Pro, MacBook Pro and more.
Upgrading the RAM in your Mac can provide a significant boost to performance, as well as equipping the machine to run demanding software in the future.
On older models this is actually a very simple procedure, and if you use third-party RAM from companies such as Crucial you’ll find the cost quite affordable too. Modern Macs are a different story, and there are plenty of pitfalls you need to avoid – which is why we’ve put together this guide.
Should I update my RAM?
Random Access Memory (RAM) is a temporary storage medium used by your Mac’s CPU. Essentially, it’s a short-lived storage space where data for processes is kept whilst you’re running them. Your CPU can access the data stored in RAM far faster than it can information held on a hard drive for example. This makes it vital to the smooth operation of your Mac.
So, is it a good idea to upgrade your RAM? Well, in many instances – yes. Put simply, RAM upgrades are one of the cheapest and easiest ways to get new life out of an old Mac. And for many models, the only tool you’ll need is a small screwdriver.
There are also a number of risks associated with updating the RAM in your Mac, which we outline below:
1. You could damage your Mac
There is the chance that if you don’t take proper antistatic precautions (which we will cover later) you could damage the sensitive electronic components inside your Mac. If you work carefully and follow the instructions you should be fine, but you undertake this work at your own risk, and Macworld does not accept responsibility if you short your motherboard or suffer similar problems.
2. A RAM upgrade may void your warranty
As a general rule, RAM is deemed as a ‘user serviceable’ part and, as such, you won’t invalidate your warranty by upgrading it. However, in the case of many modern Macs – particularly Mac laptops – Apple might specify that the memory (RAM) is not removable by users and indicate that if the RAM is to be updated it should be done by an Apple Authorized Service Provider.
With that in mind, it may be worth checking the manual of your Mac for the term “user-serviceable” to confirm this. Of course if your Mac is out of warranty then you have no reason to worry about invalidating anything.
3. The RAM might not be accessible
In some Mac models the RAM is soldered into place (e.g. 21.5in iMac 2015) so it is impossible to upgrade, and if you tried you would likely damage your Mac.
Do I need more RAM?
There are two other factors to consider before we you consider updating the RAM in your Mac: how much do you have and how much of that is your Mac using. We’ll explain how to find out the answers to both of those questions below.
How much RAM do I have?
Today’s Macs ship with no less than 8GB RAM, in many cases you’ll find 16GB RAM as standard. It’s been a long time since Apple sold Macs with anything less than that, although if you have a MacBook Air from 2015, or a Mac mini from 2014, you may only have 4GB RAM. Even older Macs will ship with even less RAM than that. On the other hand, iMacs and MacBook Pro units have offered 8GB or more for much longer.
The first step will be to find out how much RAM you have inside your Mac. It’s easy to find out.
- Click on the Apple in menu at the top of your screen.
- Click on About This Mac.
- open on System Report.
- In the Hardware overview look for the Memory section. It will tell you how much you have.
- For more information click on Memory in the column on the left.
How much RAM am I using?
The next step it to find out how much of this RAM your Mac is using at peak usage. This is the best way to find out if you need more RAM.
- Open your Mac’s Activity Monitor by pressing Command+Space and typing Activity.
- Select the Memory tab.
- Look in the section at the bottom for Memory Used.
As you can see from the screenshot above, we have 8GB RAM and are using 6.5GB, but we’re not doing anything particularly taxing right now. If we started video editing or something equally power hungry we might see a different story.
Can I add RAM to my Mac?
Having estabilished that some extra RAM may help your Mac the next big question to answer is whether you will actually be able to add RAM to your Mac. In some cases the RAM in a Mac is user upgradable, in other cases it is possible to get it upgraded by a service centre, and in some cases (unfortunately) it is not possible to update the RAM at all.
The biggest problem is that on some models, particularly MacBooks, the RAM is soldered on – making removal near impossible and hazardous to your computer. It may be possible to upgrade the RAM on these models, but it’s a risky business.
We’ll go into more detail about how to add RAM to various Mac models below. But in summary, you can add RAM to the following Macs:
- MacBook: Only the 2008 to 2011 models.
- MacBook Pro: 2009-2012 13in, 2008-2012 15in, and any 17in model can be updated. If you MacBook Pro has a Retina display the RAM can’t be updated.
- MacBook Air: You can’t update the RAM in any MacBook Air models.
- iMac: The RAM can be updated in the majority of iMacs, with a couple of exceptions: the 21.5in models from Mid-2014 and Late 2015 had their RAM soldered into place.
- Mac mini: 2010 – 2012 models can be updated, as can the 2018 Mac mini.
- Mac Pro: You can add RAM to any model.
- iMac Pro: RAM isn’t user-accessible. If the memory in your iMac Pro needs to be replaced, Apple suggests you contact an Apple Store or Apple Authorized Service Provider.
How much RAM do I need?
Hopefully you have found out that the RAM in your Mac is upgradable. In that case you might be wondering how much to get.
As a rule of thumb, 16GB is probably the most that anyone who’s not into video editing or running multiple virtual machines will need. But this is for today – a better question, perhaps, would be how much will you need years from now?
The basic principle behind Mac future-proofing is making your current hardware powerful enough to deal with the inevitable increase of software demands over the next few years. And it’s always better have a little more than you need rather than less.
Our advice would be to always bear this in mind when you are buying a new Mac. There are various build-to-order options when you purchase a new Mac from Apple, and you should get as much RAM as you can afford.
What RAM is compatible with your Mac?
This is the next challenge. Not all RAM is the same. Before you upgrade, you need to find out what kind of RAM is compatible with your Mac.
Non-upgradeable soldered RAM
As we said above, some Macs, particularly MacBooks, have RAM that is soldered on, which means it is impossible to remove it and if you try you could damage your computer. In these models you really want to buy as much as possible at the point of purchase to ‘future proof’ yourself.
Theoretically it’s possible to upgrade soldered RAM, but it is an extremely difficult process that can very likely result in the irreversible destruction of your Mac – and we certainly wouldn’t recommend it.
Types of RAM
Now, assuming your Mac’s RAM is upgradable, there are a number of technical figures used in the description of RAM, two main pieces of information you need are the ‘double data rate’ variety (i.e. DDR3), and the frequency (i.e.1600 MHz). It can also help to know your Mac’s Model Identifier (i.e. ‘MacPro6,1’)
If in doubt, ask: If you’re even a little unsure before purchasing, ask your potential RAM vendor to confirm that the components in question are compatible with your Mac. That way you’re covered.
The first and probably simplest method is to use ‘About This Mac’.
- Click the Apple logo at the top left corner, and choose ‘About This Mac’
- Look at the figure given for memory in the ‘Overview’ tab (e.g. 1866 MHz DDR3). This will tell you the kind of RAM you need
- Then click on System Rport.
- Now click on ‘Memory’ in the lefthand column. It will tell you how many memory slots you have available, and how they are being used
- You’ll also be able to see if the memory is upgradable – in the case of the MacBook Pro above it’s not.
An alternative method of identifying the correct type of RAM is to use Crucial’s free scanner. You will need to download the tool and then go to System Preferences > Security & Privacy > General > Click on Open Anyway to open the tool.
The Crucial tool will then scan your computer and let you know whether your Mac is upgradable, and if it isn’t. If the RAM is upgradable it will direct you to RAM you could purchase.
Where to buy RAM
In addition to Crucial there are lots of ways to purchase RAM. Keep in mind the general rule: cheaper = riskier.
Method 1: Direct from Apple (most expensive)
You can buy your RAM directly from Apple. It is usually the most expensive option by far and, considering that there are compatible aftermarket versions that work just as well, and are cheaper – it is not our recommended option.
Apple hasn’t currently got a RAM section in its store, so your best bet may be to go to Apple UK or Apple US and run a search for 16GB RAM or 32GB RAM, depending on how much you want to buy.
At time of writing the company sells the following RAM modules:
- 16GB DDR4 2400MHz SO-DIMM (2x8GB) – £360 (UK store) or $400 (US store). This is compatible with the 27in iMac (mid 2017)
- 16GB DDR4 2666MHz SO-DIMM (2x8GB) – £360 (UK store) or $400 (US store). This is compatible with the Mac mini (2018)
- 32GB DDR4 2666MHz SO-DIMM (2x16GB) – £720 (UK store) or $800 (US store). This is compatible with the Mac mini (2018)
- 64GB 64GB DDR4 2666MHz SO-DIMMS (2x32GB) – £1,080 (UK store) or $1,200 (US store). This is compatible with the Mac mini (2018)
If you read the description of each product, you’ll notice that the company doesn’t always tell you which Macs the RAM in question is compatible with (usually it does this only if it’s for a current Mac). So be very careful about ensuring it’s the right kind of RAM before buying.
As we said above, you are best off buying your RAM at the point that you buy your Mac, as it will be built-to-order with the RAM you require installed.
Method 2: Reputable aftermarket supplier (less expensive)
This is our recommended approach: buying your RAM through a reputable aftermarket supplier. There are plenty of places to buy RAM online, but, as with most things, established and reputable companies with warranties and return policies are your best bet.
In the world of aftermarket Apple hardware, a few names have stood the test of time. MacUpgrades, Crucial and OWC (via Megamac) are three of our favourites.
Method 3: Certified refurbished (cheaper still, but shorter warranty)
RAM refurbished by Apple or another (presumably Apple approved) company is often referred to as ‘certified’. Refurbished RAM is much less common than, say, refurbished Macs, but it does exist. Certified refurbished is often backed with a warranty, though this is often shorter than Apple’s warranty.
Method 4: Secondhand (least expensive by far, but riskiest)
We don’t recommend this. Done right, this is usually the cheapest method. It’s also the one most fraught with risk, as there is often no warranty – and no returns. You could save hundreds, or you could end up wasting money on something that doesn’t work. Caveat emptor.
There are plenty of places to buy secondhand – but when it comes to choice, eBay is probably the undisputed champion. You could also try AliExpress (which also has a lot of choice), eBid or Gumtree.
What to do before replacing your RAM
Although RAM upgrades are simple (as far as upgrades go) there are still some basic precautions that you should take when handling sensitive electronics and accessing the inside of your Mac.
The aim here is to prevent any damage caused by static electricity. This can occur when you touch an object which conducts electricity at a different electrical charge to you (yes, you conduct electricity too).
- First, shut down your Mac and wait at least 10 minutes for the internal components to cool.
- Make sure that you keep your RAM in its antistatic packaging right up until you need it. When you’re ready to start, touch an unpainted metal surface in your computer to discharge any static in your body. Try to ensure that your workplace is as static free as possible, remove any plastic bags or other objects that can cause static build up.
- Keep your Mac plugged in, but turned off. This can help ensure that the case is grounded – which reduces the chance of any discharge. The particularly hardcore may consider using an antistatic wrist or heel strap to really minimise charge build up – but this isn’t essential.
- When mounting your RAM, ensure that the small notch cut into the front facing gold contacts matches up with the protrusion in the receiving bay. Mounted correctly, it will slot in, jigsaw-like – if mounted the wrong way, the protrusion will prevent the RAM from fully connecting.
How to upgrade MacBook Pro RAM
After the arrival of the Retina display, upgrading your Mac laptop, be it MacBook, MacBook Air or MacBook Pro became nearly impossible. If that’s the Mac you own then the upgrade will be tricky or, more likely, impossible.
However, if your MacBook Pro was originally purchased prior to 2012 then you should be able to update the RAM.
A more extensive list of upgradable MacBooks would be:
- MacBook: Only the 2008 to 2011 models.
- MacBook Pro: 2009-2012 13in, 2008-2012 15in, and any 17in model can be updated.
Models produced prior to 2012 are relatively straightforward to update, though there are some obvious structural differences in the design of the Air, Pro and original MacBook.
MacBook Pro RAM update
If your MacBook Pro is from 2009 to 2012 the following guide should apply to you:
- Shut down your Mac, unplug it and wait a while to make sure all the components are cool.
- Remove the bottom part of the case while keeping track of all the screws (there are 10 screws of different lengths, so it’s worth sticking them to an A4 sheet of paper in the correct locations)
- Before moving on you should touch something metal to discharge any static electricity you have picked up.
- You should be able to see the existing RAM. Remove this by pushing the levers on either side. Before lifting out the memory locate the notches – if you can’t find them press out the levers again. Lift out the memory (hold it by the sides and be careful not to touch the gold connectors).
- To insert the new RAM alligh the notch on the module with the notch in the memory slot – you need to have the gold side up. Push the memory in.
- Push down on the memory to click it into place.
- Now replace the bottom of the case using your carefully labled screws (you did keep track of them right!)
How to upgrade Mac mini RAM
Up until late 2014 the Mac mini was a very easy device to upgrade yourself. Simply unscrew the plastic base and there were two pop-up RAM slots into which you could place new chips. If you have one of these models then it’s probably fitted with 4GB of RAM, as that was the standard Apple issue.
Sadly the 2014 Mac mini removed the manual upgrade feature of its predecessore. It was only possible to upgrade at point of sale, otherwise it came with 4GB fitted, which can be increased to either 8GB for £90/$100 or 16GB for £270/$300. The two higher models both come with 8GB of RAM, which again can be increased to 16GB.
In the years that followed the Mac mini was not ‘RAM upgrade friendly’ with quite a lot of variation in the internal layout of the various models, which meant that some require more disassembly than others. There is sometimes the need to unplug components on the logic board, which can end badly if you’re not careful.
Thankfully, when Apple updated the Mac mini in 2018 changes were made that made it more upgradable – although Apple indicates that the upgrade should be done by ab Authorised Service Provider (that won’t stop savvy upgraders though). That machine can accomodate up to 64GB RAM.
Here’s a list of upgradable Mac minis:
- 2018 Mac mini – not officially user-upgradable, but you can get the memory updated by an Authorised Service Provider.
- 2010-2012 Mac mini – user upgradable.
Mac mini RAM update
If you have a model from 2010 to 2012 the following steps should apply to you:
- Start by turning off the Mac mini and disconnect it from power.
- Lay your Mac mini upside down so you can see the bottom cover. Rotate the cover anticlockwise to unlock it.
- Pressing the cover should cause it to pop out.
- Remove the existing memory – you’ll need to push out the clips at either end of the memory before you can pull the memory out.
- You can now install the new memory.
- Replace the cover – you need to match up the dots before you can screw it back into the locked position.
How to upgrade iMac RAM
Upgrading an iMac’s RAM is, at least in the case of the 27in model, easier than upgrading its other components – as it doesn’t generally involve removing the screen.
It is a lot easier to upgrade the RAM in a 27in iMac than in the 21.5in iMac because the 27in model has a convenient memory access door, located centre beneath the screen – where RAM can be accessed (as per our image below). In that case updating the RAM is simple, you just need to make sure you purchase the correct RAM and you are all set.
However, the RAM in the 21.5in iMac can be a little more tricky to update, and in some generations (namely the Mid-2014 and Late 2015 models) it’s impossible to update due to being soldered into place.
Thankfully, Apple’s stopped soldering RAM in place in recent years. Now even 21.5in iMacs can be upgraded, but it’s a challenge best left to an Apple Authorized Service Provider.
Here’s our list of upgradable iMacs:
- 27in iMac: The RAM can be updated.
- 21.5in iMac: The RAM can be updated in the majority of 21.5in iMacs, with a couple of exceptions: the Mid-2014 and Late 2015 21.5in models had their RAM soldered into place.
- iMac Pro: RAM isn’t user-accessible. If the memory in your iMac Pro needs to be replaced, Apple suggests you contact an Apple Store or Apple Authorized Service Provider.
27in iMac RAM update
In this example we update the RAM in a 27in iMac. It’s a pretty easy process.
- Place the iMac flatscreen down on something soft (such as a towel or blanket) to protect the screen.
- Press the small button at the top of the power socket, and pick out the memory hatch door above it. This is quite possible to do using just your fingers.
- Try to avoid using something to help lever the door open as you might scratch your Mac. Get someone with longer, strong fingernails if that helps. You really don’t need much pressure to open this door.
- You’ll now see the two 4GB memory DIMMs that Apple ships as standard with its iMacs. The company illustrates how the RAM should be fitted on the back of the memory hatch door.
- Now pull out the little arms to raise the iMac RAM slots.
- Add your two new DIMMs in the empty slots. There’s no need to remove the existing memory chips, unless you’re adding four new 8GB DIMMs for the maximum 32GB memory installation.
- Press back the small levers so that the DIMMs are back flat.
- Put the door back on so that it clicks back into place. You don’t need long fingernails for this!
21.5in iMac RAM update
In this example we update the RAM in the mid 21.5in iMac from 2010. As we mentioned above, the RAM in the 21.5in iMac between Mid-2014 and Late 2015 wasn’t upgradable.
As long as you aren’t updating a 2014/2015 model, the process should be similar to that outlined below.
- Lay your iMac face down on a clean, soft surface. We recommend that you place a towel beneath your Mac and your work surface – you don’t want to scratch your screen.
- Find the RAM access door at the bottom of your Mac. Loosen the three screws that secure it, they should remain inside the access door, then remove the door.
- Carefully slide the black RAM pull tab out of the slot.
- Firmly push this tab to eject the module on this side of the RAM bay.
- Slide the RAM module out of its slot in the bay, and set aside. Repeat this process to remove RAM modules from other bays.
- Ensure that replacement RAM modules are correctly oriented, and then gently slide them into the iMac. Make sure they’re mounted by using your thumb.
How to upgrade iMac Pro RAM
It might look like the same exterior design in most respects, but the iMac Pro hasn’t got the same user-accessible hatch as the iMac, so you can’t upgrade its RAM yourself.
The good news is that you can get the RAM upgraded, you just need to go to a service centre and ask them to upgrade it for you. Rene Ritchie says this doesn’t need to be an Apple Store – it can be an independent outlet.
How to upgrade Mac Pro RAM
The Mac Pro used to be is Apple’s most ‘upgrade-friendly’ product. Even the 2013 Mac Pro had a memory bay, although it is somewhat fiddly to access.
The RAM inside Apple’s new Mac Pro that launched at the end of 2019 is also user upgradable.
Mac Pro (2013) RAM update
It’s worth bearing in mind that the memory latches are not very sturdy and prone to bending if you’re not careful. OWC provides a ‘nylon pry tool’ (AKA “Spudger”) for just this, but it’s not entirely necessary – a little gentleness and a little patience go a long way.
Apple provides an illustrated guide for memory upgrades: just click Apple > About this Mac, and then click the Memory tab and then the Memory Upgrade Instructions link.
- Slide the lock switch right, to the unlocked position, then slide the outer case upwards and off the Mac Pro.
- Push the RAM release tab upwards (in the direction of the white arrow). This will cause the RAM slots to release outwards, and allow you access to the modules.
- Gently, but firmly, grasp the top and bottom of the RAM module and pull it out of the slot.
- To install the new module(s) ensure that it is oriented correctly, and then push the ram into the slot, make sure that you apply pressure to the top and the bottom of the chip, to ensure that it is fully mounted
- Push the tray back into the body of the Mac Pro and then replace and lock the case.
Mac Pro Tower (pre 2012) RAM update
- Lift the locking lever on the back of the case to unlock the side panel, then remove the side panel.
- Locate the RAM tray at the bottom corner of the Mac Pro.
- Simultaneously push downward on the ejectors on each side of the RAM stick; this should cause the RAM to release. Then carefully lift the stick out.
- Ensure that the new stick is properly oriented, then carefully push the stick down into the bay with both hands, ensuring that you put some pressure on both ends of the stick. You should hear a click as the ejectors lock the stick in. Make sure both ejectors are secured.
What to do after replacing your RAM
Once you’ve completed your upgrade, it’s a safe bet to run a memory test on your new modules – to ensure that everything actually works.
Why? Often it’s not obvious if a piece of RAM is not up to par. Occasionally a defective chip will make its way through the manufacturer’s quality tests – and a memory test can help you prevent problems before you start to experience crashes and similar calamities.
If for some reason Memtest is not for you, there are a number of alternatives in the App Store – search for ‘Memory Test’ software, but check the reviews first. We’ve not tested any of them and can only vouch for Memtest.
You can also use your Mac’s inbuilt memory tests. Restart or boot up your Mac, and hold D whilst it boots – this should take you to the diagnostics screen. What actually comes up at this point will depend upon your OS, but somewhere in the options should be a section called ‘Hardware Tests’ – in which you’ll find the option to test your memory.
Today on memory chip retailer Crucial’s website you can buy an 8GB kit for £59.99 or 16GB kit for £91.19, (both for the 2012 genertion Mac mini) or a 16GB kit for £92.39 and a 32GB kit for £179.99 (for the 2018 Mac mini).
Depending on the model you’re working with, it’s likely that you’ll need some kind of flat implement to get the top cover off (blunt, not sharp). Don’t let that stop you, though – our colleagues in the US managed to do it in a mere 6 minutes, but it was a very old Mac mini model.