Upgrading 2013 iMac to SSD

Bought a used 21.5” 2013 iMac for $300 that has a 1TB HDD in it now. Would like to upgrade to an SSD to make it more snappy…

What’s involved with making the change? Is it relatively easy to do and can someone point me to a walkthrough of the process including installing the OS?

OWC has drives and associated video instruction for both the Early 2013 iMac as well as the Late 2013 model. Go to the Videos section and choose your specific model.

1 Like

I couldn’t find the video for the early 2013 but I took a quick look at the one for the late 2013. I consider myself pretty adept at digging into a computer’s guts but I would be leery trying this one myself. The display is glued in and it looks pretty iffy getting it open.

I agree. Those models have USB 3.0, Thunderbolt and Ethernet - I’d just connect an external SSD and experiment with a partition to see if the SSD as startup drive felt faster than the internal HD.

Here’s some info on external nvme.


The display is not glued on… it is held in place with VHB (very high bond) adhesive a.k.a. 2 sided tape. I believe fixit.com has a video showing how to DIY and they also sell the tool that cuts thru the tape as well as replacement VHB strips.

Is this a job for the timid? No

Is it really that hard? Not if you are careful.

The 21.5" iMac is a 2.5" HD so replacing it with an SSD is fairly straight forward. The 27" iMac still uses the 3.5" HD.

I’ve noticed it really struggles to run launch programs, even simple ones. It has 8gb of RAM so I’m debating taking it to a Apple Authorized Repair and paying for the SSD conversion and moving it to 16GB of RAM. Is there any reason to believe after these upgrades are done that this machine wouldn’t be up to most any normal uses short of heavy load graphic work?

I imagine it would be rather expensive (to put it mildly) to have this work done professionally.

That machine could have a i3, i5, or i7 processor. Since your machine has a 1 TB HDD I’m guessing it is not the i3, but in all of them the RAM is “not intended to be replaced” (per everymac.com). I don’t know if this means it can’t be done (actually the phrasing seems odd to me). As @MacGuyMI pointed out, the actual replacement of the HDD is pretty trivial.

Only you can decide how much you want to spend on this. Maybe you can get a rough estimate over the phone or by email.

You may want to consider purchasing an external thunderbolt SSD and install MacOS on this SSD. Use your current internal spinning HD for storage. This made a big difference for my wife’s 2013 21.5 inch iMac/8 GB RAM. Buy one with a good return policy in case it doesn’t meet your expectations.

As noted above, I would suggest an NVME drive. Here are some benchmarks I did. You can see the relative differences between the NVME drive, and the Crucial SSD just below it in the table.

2 things,

  1. Do you have any suggestions on one?

  2. How hard is it to image an external SSD to run as the OS? Do you have a link to a walkthrough of the process?

1 - I used a LaCie Rugged external SSD but that was 4.5 years ago - still working fine. Other external SSDs that I have used include Samsung T5 and SanDisk Extreme Pro. All work fine.

2 - This is what did, but you can format as APFS: https://duckduckgo.com/?q=install+mac+os+catalina+on+external+ssd&t=osx&pn=1&iax=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DkdzK5lgqLjM&ia=videos

The external SSD that I use is 250GB. The iMac’s internal HD is 1 TB. After I made sure that the external SSD worked well as a startup drive, I reformatted the iMac’s internal HD to be used for storage. I described what I did in this thread: OS on external SSD, leave data on spinning drive?

Before doing anything make sure you have good backups of everything.

Also, I’m sure others will have suggestions as to a good external SDD.

The 2013 iMacs (as well as early and late 2014 iMacs) have Thunderbolt 2 ports (not Thunderbolt 3). Be advised that newer model Thunderbolt 3 external SSDs will probably need some type of conversion from Thunderbolt 2 to Thunderbolt 3.

I have no experience with thunderbolt conversion cables or dongles, but I have read elsewhere that these could be problematic.

1 Like

It’s probably been at least 3 years since the last time I had an iMac HD replaced, but it was only costing me $100 plus the cost of the new drive (spinning) at that time. Might be worth a call to get a quote.


I think the advice of using an external SSD is good. Find one that is Thunderbolt 2 equipped because YOUR iMac only has Thunderbolt 1 connectivity. 2013 iMac (both early and late 2013) models did not have Thunderbolt 2 speeds according to MacTracker and my brain cells.

The cost of upgrading the internal HD and Memory should run around $300US per your specs. But that is what you paid for this iMac already. Might not be a bad investment but it is your money…

I’m running virtual machines on one of these drives. It works fine on my 2015 MBP with a USB-A to USB-C adapter that was included, as well as my iMac Pro. I run Windows, Ubuntu, and Fedora, and they all run fine. I have no complaints about speed.


I ended up picking up a Sandisk Extreme SSD 256gb yesterday at Walmart for $60. Came home and setup Catalina and now it’s running perfectly. I’m so amazed how well this 7 year old iMac is running for under $400. Fantastic!

Thanks for the directions everybody!!!


We upgraded our late-2012 iMac to an external SSD a year or two ago and it’s been a game-changer.

Here’s a link to that thread.

Bottom line: the internal spinning drive is not used. Just has a clean-install of the OS (which needs to be updated at this point…). All the action happens on the external USB. What we purchased at the time is below:

SSD Enclosure


1 Like