Operating system
Logic board etc
iMac 27″, OS X 10.11
1) It will cost more than the iMac is worth.
2) Upgrading an Obsolete iMac is a waste of time and money.
3) It will never be able to run anything later than macOS Catalina which is not longer supported.
I recommend recycling and replacing it with a new iMac or Mac mini and external display.
$0. Operating System updates are free.
A 2013 iMac can update to macOS 10.15 Catalina but no further.
Logic Boards cannot be upgraded. It's essentially replacing the entire computer and logic boards from newer computers will not work in an older chassis with different connections.
You could add RAM and storage (SSD) but honestly on a 12 year old iMac it's not going to make much difference, you won't be able to upgrade to a newer macOS version regardless of how much RAM and storage you throw at it.
Any money you are planning to spend in upgrades is best served being put towards buying a newer model. Does not have to be a current model.
You can get a brand new Mac mini for $550, which at the end of the day, won't be too far off what you would spend on this iMac adding a new logic board (if that were possible) RAM and SSD.
You can't update an iMac (27-inch, Late 2013) past macOS 10.15.7 (Catalina) – an operating system which has not been supported by vendors like Microsoft and Adobe for some time now.
Catalina is enough to run current versions of
Even that could change at any time.
Note that Catalina breaks 32-bit software. If you are still running El Capitan (as your tag line suggests), you might want to take that into account when making the decision as to whether to upgrade all the way to Catalina.
How to download and install macOS - Apple Support
That iMac has four user-accessible RAM slots and can take up to 32 GB of RAM. If you get more RAM, I'd strongly advise buying it only from Other World Computing. Macs can be picky about RAM – and the other go-to Mac RAM vendor (Crucial) no longer seems to be in that business.
OWC Memory Upgrades For 27" iMac (2012 - 2013)
Upgrading the internal drive is trickier, and you'd probably be better off connecting an external SSD via one of that Mac's four USB-A (USB 3.0) ports.
It will cost you the price of a new(er) Mac.
You can only upgrade the memory and internal drives on an old 27" iMac. Logic boards are not interchangeable.
If you're considering getting a new Mac consider the following: a 10 Core Mac Mini M4 with 16 GB RAM and 1 TB SSD ($999 US) with a 27" LG 4k monitor ($250 US) from Amazon.com) is $1249 US which is $560 less than a similarly configured new 24" iMac ($1799 US) re 07/2025. You get much more bang for your buck with a Mini.
Just some food for thought.
Short answer: Get a new iMac. They start at $1299. Most likely, less than the cost of any upgrades that are even remotely possible with a 2013 iMac.
what would it cost to upgrade my 2013 iMac?
