iMac "Core i5" 3.1 27-Inch (5K, 2020)

Here you can find the exact specifications of this Mac, along with guaranteed compatible upgrades for it.

  • Part Number: MXWT2LL/A
  • Model: iMac Retina 5K 2020 27"
  • EMC Number: 3442
  • Model Identifier: iMac20,1
  • Model Number: A2115
  • Introduced: 2020
  • Discontinued: Current Model
  • Max Operating System Version: macOS 12 Monterey (Current) (download)
  • Earliest Supported macOS: macOS 10.15.6 Catalina
Links to download compatible macOS from Apple
  • CPU Speed: 3.1GHz
  • RAM Type: DDR4 SODIMM 2666MHz
  • RAM Slots: 4
  • Max RAM by Slot: 4 x 32GB
  • Maximum RAM: 128GB
  • RAM Pairing: There is a benefit but not a requirement to install RAM in matched groups of 4
  • Device Connectivity: USB 3, USB-C, Thunderbolt 3
  • Bluetooth: 5.0
  • Video Output: 2 x Thunderbolt 3
  • Revision Produced From (Year): 2020
  • Repair and Upgrade guides: From
100% Compatability Guarantee
  • RAM Upgrades
  • Internal Drives
  • External Drives
  • CD/DVD/Blu-ray Drives
  • Expansion Cards
  • Batteries & Power Supplies
  • Graphics & Displays
  • Keyboards, Mice & Trackpads
  • Cables, Adaptors & Tools
  • Repairs
  • Configure RAM & Drive Upgrades
  • RAM Type: DDR4 SODIMM 2666MHz
  • RAM Slots: 4
  • Max RAM by Slot: 4 x 32GB
  • Maximum RAM: 128GB
  • RAM Pairing: There is a benefit but not a requirement to install RAM in matched groups of 4

Compatible RAM for this Mac

What is RAM and how does it help? - Click here for more info

RAM stands for Random Access Memory, it is a short term store for data which is only used while the machine is in operation. This is not where your data and applications are stored (that's the Hard Drive or Solid State Drive) so RAM can be replaced without worrying about any data transfer issues.

How much RAM you need depends very much on what you are doing with your Mac. Adding more and more RAM does not necessarily speed your machine up - rather the better way to think about it is that not having enough RAM will slow you down. When your system runs out of physical memory it will use virtual memory on your hard drive instead, this is orders of magnitude slower than RAM, and will result in more instances of the spinning wheel or stuttering.

The more RAM you have, the more things you can do at once and you are able to switch between them better. Also as later operating systems come along they have greater requirements, so a machine feeling fast running OSX 10.7 with 4GB of RAM may well feel sluggish in OSX 10.10 with the same.

Here are the amounts of RAM we have found to be the real minimum for comfortable use in different operating systems. The minimum levels here are not absolute, but even lighter users will be well advised to take steps to minimise RAM use (principly restricting the number of applications they use simultaneously) if they are below them. Of course for some more specialist users of RAM intensive applications, even the ideal amounts listed will be grossly inadequate.

  • Mac OSX 10.6 Snow Leopard - Min 2GB, ideal 4GB or above
  • Mac OSX 10.7 Lion and 10.8 Mountain Lion - Min 4GB, ideal 6GB or above
  • Mac OSX 10.9 Mavericks,10.10 Yosemite, 10.11 El Capitan - Min 6GB, ideal 8GB or above
  • macOS 10.12 Sierra and Later - Minimum 8GB, and this is generally reasonable for light usage though 16GB is more comfortable.

Some systems may not be able to use these amounts but will still run the newer OSs, in these cases maximising your RAM will be the best you can do. To get a better idea of your own specific RAM requirements, you can use the Activity Monitor utility built into macOS. This will let you see how much RAM you really need while using your Mac in the way you use it. Activity Monitor is inside your Utilities folder, which is inside your Applications folder. Apple have an in-depth explanation of how to use Activity Monitor here.

There are lots of different types of RAM. The RAM modules and compatability information below was generated from the Serial Number or Model ID you selected, and is guaranteed to work 100% or your money back. Even if your manual says otherwise! Original manuals, and even online documentation, are not updated after a machine is released and therefore not up to date with the actual maximum RAM that can be used. Many machines can make full use of more RAM than the offical spec, and we guarantee that the maximum amounts we list will work flawlessly, and be fully utilised by your Mac.

Installation Services

Don't want to fit the RAM yourself? Have us install it for you - full details here.

Compatible External Optical Drives for this Mac

Sorry, nothing available.

Sorry, nothing available.

Sorry, nothing available.

Keyboards & Mice

Bluetooth Keyboards

USB Mice

Sorry, nothing available.

Compatible Cables, Adaptors and Tools for this Mac

Thunderbolt 4 40Gb/s


USB 3.0

Tools for this Mac

Compatible External Drives and Enclosures

External SSDs

External Hard Drives

External Drive Enclosures

Repair and Installation Services

See repair guides from

Here are our list of fixed cost repair and installation services for this Mac. All machines for repair or upgrade can either be shipped to us (we can arrange collection if desired), or you are welcome to drop the machine into our offices in Sawston, Cambridge. We have been doing Apple Mac repairs since 2001, you can be assured of a complete, speedy, good value and professional service.


Installation Services (parts not included)

Configure RAM & Drive Upgrades

You can use this tool to build an upgrade order and have us. Using this tool will also generate a link you can use to create this order again yourself, or share with someone else.

Note: This tool only selects from in stock products. Items that are out of stock, or special order items with extended lead times, can be added to your order from the other tabs.

RAM Upgrades

Select RAM to upgrade your machine from the drop down below. Note that you have 4 RAM sockets in this machine. Depending on how much memory is currently installed you may need to remove the existing RAM before fitting more.

Internal Drives not found: Either we have been unable to determine enough information about this Mac needs from the serial number, or we do not have any in stock for this model. You can add drives to this order manually later from elsewhere on our site if you know what type it needs - call, email or chat to us if you need help!

Installation Services

- details here

If required, we can fit your new components for you. Note, if we are fitting multiple parts, you do not need to pay separately for each of them to be fitted - the order created will include only the most expensive fitting service.

Have us fit RAM? - Cost: £10.00 + vat

If we are shipping the upgrades to you for you to install yourself, please choose a delivery option during checkout.

If we are fitting the parts for you, you need to get the machine to us. You can either bring it to our Cambridge location, or ship to us via any method you choose, or you can have us send our courier (DPD Local) to collect it. Collection costs £24.68 + vat and the machine must be packaged for transit with at least 2 to 3 inches of packing material around each dimension (note: iMacs should only be shipped in their original box with their original packing inserts). You can specify any working day for collection, but you cannot choose a time. For any weight under 10kg we advise people to ship the machine themselves via Royal Mail Special Delivery - you can get a tracked next-day delivery with additional insurance for less than our collection service, and it is generally more convenient than waiting in for a courier.

Have us send our courier to collect?

Return shipping (or collection by yourself) is chosen when you check the order out.

With this box checked, the upgrade order will replace any items in your cart. If you want to add it to items already in the cart, please uncheck this box.