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Memory Trade in
Save money by trading in your original chips! View available memory rebates.
From the purchase date of qualifying memory from OWC, you have 60 days to trade-in your old memory for a cash rebate!
Just fill out OWC's online rebate form or contact OWC Customer Service after you receive and install your new memory.
Please note:

For the 21.5" iMac, it is strongly recommended that you purchase a memory upgrade kit designed specifically for the 21.5" iMac. This machine requires tools to open and adhesive to reseal.


This OWC Memory is compatible with... Learn how to find your Mac's model ID or PC specs
iMac Intel
iMac w/Retina 5K display
(27-inch Mid 2017)
(June 2017)
Model ID:iMac18,3
3.4GHz i5, 3.5GHz i5, 3.8GHz i5, 4.2GHz i7
iMac Intel
iMac w/Retina 4K display
(21.5-inch Mid 2017)
(June 2017)
Model ID:iMac18,2
3.0GHz i5, 3.4GHz i5, 3.6GHz i7
iMac Intel
iMac (21.5-inch Mid 2017)
(June 2017)
Model ID:iMac18,1
2.3GHz i5

Customer Ratings

Write a Review 4.9 / 5 34 out of 36 (94%) reviewers would recommend this product
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Verified Buyer
Reviewer: NopSled Location: Grovetown, GA Age: 45-54 Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 Performs Perfectly! September 2, 2018 Installed the 4 DIMMS into my new iMac with no issues. I've experienced none of the quirky system issues that are normally associated with RAM. This memory has performed perfectly!

I would recommend this item to a friend! This review is from 64.0GB (4x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: ManyPhotos Location: Dallas, Texas Age: 55-65 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Don't panic after installing your RAM! August 20, 2018 I just bought a new 27" iMac 5K and added the OWC 32 GB RAM kit to it before I even plugged it in. The process is very quick and very easy -- it took maybe two or three minutes. No problem -- but be aware. The machine would not turn on when I first plugged it in, so I looked up the symptoms on my phone and was relieved to discover that it's normal. Newer Macs have to initialize any RAM when it is first installed or the RAM configuration is changed. I just followed the recommended routine -- unplug the machine, hold down the I/0 button for at least ten seconds, then plug it in and hold the button in again until it starts up. Everything boots properly and you're off and running. As I don't buy new Macs often, I was unaware of this change. But panic averted, I have a new machine with plenty of RAM and everything working just the way it should!

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: LensguySteve Location: Southampton Age: 55-65 Experience Level: Power User Owned Product: less than a month
Rating: 5/5 Works as described, without a hitch! August 20, 2018 Easy to install, fast shipping, less expensive than competitors, what else can I say...... oh yea Works Great!!

I would recommend this item to a friend! This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: DarthXoc
Rating: 5/5 Works great; turns the iMac into a real powerhouse! July 23, 2018 I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:
Verified Buyer
Reviewer: DarthXoc
Rating: 5/5 Excellent value compared to Apple's prices! June 24, 2018 I would recommend this item to a friend! This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:
Verified Buyer
Reviewer: Deelee Location: Ithaca, NY Experience Level: Noob Owned Product: less than a month
Rating: 5/5 Easy to install June 19, 2018 The order came quickly. The memory was extremely easy to install. Computer recognises it as such, so we are good to go!

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: virtualmeida Location: denver Age: 55-65 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Easy install - works great June 11, 2018 Put this into our new iMac 27" 5K, kept the existing stock RAM in place & added an additional 32Gb of RAM. Love buying from OWC, you know their products work & easy install,

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: troy20 Location: NYC Age: 35-44 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 32.0GB OWC Memory Upgrade Kit for iMac 27" 2017 with Retina 5K June 6, 2018 First of all, I have been a Macsales customer since 1990's. Everything I have purchased from them worked perfectly. I have a new iMac 27" 2017 5K w/ 3.4 processor. Like all iMacs it came w/ 8GB stock memory which is not adequate to run today's software. So, I purchased 32GB upgrade (2x16). Now I have a total of 40GB memory (32+8=40). It is a good idea to get two 16GB's because if you need to upgrade it to 64GB maximum in the future you can add just another pair of 2 x16 memory! Installation was really easy. Just unplug your iMac, put it on a soft surface screen face down. Press the memory cabinet cover pop up button down, slide in your new memory sticks, power up your computer and you're done. Note that you need to press the button really hard in order to pop up the cover. I used wood chopsticks to not to scratch my computer. Also, make sure to slide your memory in a correct way. It should be firmly in place and should not move. Today is my second day after upgrade and I am very happy w/ awesome performance.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Aclarion Location: New York Age: 45-54 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 Excellent Service June 3, 2018 Great Price and fast shipping. The extra memory has improved performance.

I would recommend this item to a friend! This review is from 8.0GB (2x 4GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: saltydog Location: Ottawa Age: 45-54 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 Plug and play May 17, 2018 New ram was easy to install and works great.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: thedvsmonkey Location: Virginia Beach VA Age: 45-54 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 No Brainer! May 1, 2018 I honestly feel this is a no brainer! I boosted my iMac from 8Gb to 16Gb with 2X4Gb chips from OWC. I then decided it was necessary to just get a 32Gb set to boost to 40Gb. I do not regret this one bit and my iMac flies! Don't waste money buying the ram from Apple! I'm almost tempted to get another 32Gb from OWC and just max out the iMac.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Aceman Location: Newton, MA Experience Level: Power User Owned Product: less than a month
Rating: 5/5 Blazing Speed! April 30, 2018 Turned my iMac into a rocket! Don't buy directly from Apple and get ripped off. Buy from OWC and save a ton.

I would recommend this item to a friend! This review is from 64.0GB (4x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: topspincharlie Location: Crofton, MD Age: 35-44 Experience Level: IT Professional Owned Product: less than a month
Rating: 5/5 Cost effective way to max out imac and save $720 April 29, 2018 Very easy to install, saves ~$720 off of purchasing imac with this memory.

I would recommend this item to a friend! This review is from 64.0GB (4x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: xABD Location: Western TN Age: Over 65 Experience Level: Power User Owned Product: less than a month
Rating: 5/5 You can't have too much RAM! April 25, 2018 Bought a new iMac with minimum RAM fully intending to use third-party memory sticks. I have always had great experiences with OWC and found their 16GB modules were my best choice. Installation is a breeze and the chip has performed flawlessly!

I would recommend this item to a friend! This review is from 16.0GB 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade. Customer Videos:

Verified Buyer
Reviewer: vailtc Location: Colorado Age: 55-65 Experience Level: Power User Owned Product: less than a month
Rating: 5/5 Works great! April 9, 2018 Works just like it is supposed to. Easy to install. Directions simple to follow.

I would recommend this item to a friend! This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: 2010Imac Location: West Virginia Age: 25-34 Experience Level: Home User Owned Product: over 6 months
Rating: 5/5 works April 2, 2018 works. way cheaper than apple. Only in use for a day or so but works great.

I would recommend this item to a friend! This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Flept Location: USA Owned Product: less than a month
Rating: 5/5 Great March 29, 2018 The memory works perfectly.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: horseman Location: Waterford NJ Age: Over 65 Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 Works and installs easily March 21, 2018 Purchased a 16 GB RAM upgrade for a 27" iMac. RAM was delivered promptly and installed easily. New RAM worked exactly as expected.

I would recommend this item to a friend! This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Mbmatt Location: Yellowknife, NT Age: 45-54 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 Great product March 11, 2018 Not really much to say about this. The shipping was extremely quick, the RAM arrived before my 2017 iMac which I was hoping for. Not much else to say great product, good company for what I required.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Sandydog21 Location: Long Island, NY Age: Over 65 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 This product was very easy to install and works great! March 8, 2018 I bought 32 Gigs memory for my IMAC 27” fall 2017 model.. running photoshop and Lightroom at the same with the 8 gigs I had was becoming a nightmare. The memory was very easy to install and made running the 2 programs together a breeze. The speed was immediately noticeable.. This company’s website was easy to use and the service excellent..

This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: Sheyingshi Location: Lakewood, WA Age: Over 65 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Good Product, Good Service March 8, 2018 Been using Other World Computing since forever and never had a problem. Way back in the '90's they were about the only people who sold upgrades for Macs and that's what got me started. So they still go a good job and their products are quality. So I still come back.

This review is from 16.0GB (2x 8GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: fonturbel Location: Santiago, Chile Age: 35-44 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Excellent product and price March 2, 2018 I bought a 32-Gb upgrade for my shiny new 2017 retina iMac and I could not be happier with the purchase... now my iMac has 40 Gb of RAM, the performance has improved a lot, especially when executing virtual machines in Parallels and apps that need lots of memory to perform well (e.g., analyzing large datasets in R).

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: KerryDawson Location: Toronto ON Age: Over 65 Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 The Best Thing I could ever have done for my Mac February 18, 2018 I just bought a new iMac with 32 gigs memory. I wanted 64 but Apple talked me out of it (they are so stupid and dare I say it greedy as they won't upgrade you after the fact presupposing you'll just pop down another 5k to buy a new machine). I contacted Macsales and a 64 gig ram set was less thsn if I had ordered it from Apple. Apple made me feel this was hard to do. It was a breeze. I now have a 64 gig iMac with an SSD drive (be careful as Apple made all the SSD machines AFPS and it came out a year too soon) and my computer is purring. It has never run so well no thanks to Apple.

I'd heartily recommend the 64 gig ram upgrade from Macsales who notices too much paging activity or RAM flushing. Welcome to the new Apple far more sinister than the old Microsoft ever was thanks to Tim Cook.

I would recommend this item to a friend! This review is from 64.0GB (4x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: EasyT Location: Texas Age: Over 65 Experience Level: Home User Owned Product: 1-3 months
Rating: 5/5 Outstanding! February 14, 2018 Easy to do just plug and play. Price was equal to the competition.

I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:

Verified Buyer
Reviewer: RLynch Location: KY Age: 45-54 Experience Level: Home User Owned Product: less than a month
Rating: 5/5 Working great, easy to install February 12, 2018 I would recommend this item to a friend! This review is from 32.0GB (2x 16GB) 2400MHz DDR4 SO-DIMM PC4-19200 SO-DIMM 260 Pin CL17 Memory Upgrade Kit. Customer Videos:
OWC Memory 4.0GB 4GB PC4-19200 DDR4 Mfr P/N: 2400DDR4S4GB OWC SKU: OWC2400DDR4S4GB OWC Memory Upgrade Kit Lifetime OWC Limited Warranty Ships: Same Day only $49.99
Add to CartOther World Computing 2400DDR4S4GB In Stock, Click to Buy Now
Additional Capacities & Kits:
  • 4GB
  • 8GB (2x4)
    • Ships: Same Day
    • Only $99.98
    • OWC Price $97.99
  • 8GB
    • Ships: Same Day
    • Only $99.97
    • OWC Price $99.97
  • 16GB
    • Ships: Same Day
    • Only $169.99
    • OWC Price $169.99
  • 16GB (2x8)
    • Ships: Same Day
    • Only $199.94
    • Matched Kit for $194.99
  • 32GB (2x16)
    • Ships: Same Day
    • Only $339.98
    • Matched Kit for $319.99
  • 32GB (4x8)
    • Ships: Same Day
    • Only $399.88
    • Matched Kit for $379.99
  • 64GB (4x16)
    • Ships: Same Day
    • Only $679.96
    • Matched Kit for $629.99