OWC 128GB (4 x 32GB) PC21300 DDR4 2666MHz 260pin SO-DIMMs Memory Ram Upgrade Compatible with 27" iMac w/Retina 5K (Early 2019 and up) and Compatible PCs (OWC2666DR4S128S)
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30-day refund/replacement
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
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Availability:
In Stock.
Arrives
Friday, Jul 4
Size: 128gb
Color: 4 x 32GB
Features
- OWC 256.0GB UPGRADE: Consists of Four 32GB DDR4 2666MHz PC4-21300 CL19 SO-DIMMs 1.2V 260-pin Memory Module Fully compliant with JEDEC specifications, ROHS compliant, warranty safe upgrade; Backed by OWC Memory Lifetime Limited Warranty including the OWC Lifetime Advanced Replacement Program
- COMPATIBLE WITH: 2020 iMac: iMac w/Retina 5K display (27 inch mid 2020) Model ID: iMac20,1 and iMac20,2 (3.1GHz i5, 3.3GHz i5, 3.8GHz i7, 3.6GHz i9)
- COMPATIBLE WITH: 2019 iMac: iMac w/Retina 5K display (27-inch Early 2019) Model ID: iMac19,1 (3.0GHz i5, 3.1GHz i5, 3.7GHz i5, 3.6GHz i9) Models: MRQY2LL/A, MRR02LL/A, MRR12LL/A
- PC COMPATIBLE WITH: works with compatible gaming laptops and PC desktops: Dell, HP , Toshiba, ASUS, Acer, Supermicro, Fujitsu, Gigabyte, Intel, Lenovo, LG, Samsung, Sony, Supermicro
- COMPATIBLE PART NUMBERS: CT2K32G4S266M, CT32G4S266M, KCP426SD8/32, CT32G4SFD8266, HMAA4GS6AJR8N-VK, M471A4G43MB1CTD, MUQQ2G/A
- INDUSTRY LEADING: Consumer Friendly Advanced Replacement Program and Limited Lifetime Warranty, which Includes Free Tech Support by Other World Computing
Brand: OWC
Computer Memory Size: 128 GB
RAM Memory Technology: DDR4
Memory Speed: 1333 MHz
Compatible Devices: Desktop
RAM: 128 GB DDR4
Brand: OWC
Series: OWC2666DR4S128S
Item model number: 2666DR4S128S
Item Weight: 2.08 ounces
Product Dimensions: 6.26 x 4.25 x 0.28 inches
Item Dimensions LxWxH: 6.26 x 4.25 x 0.28 inches
Color: 4 x 32GB
Computer Memory Type: DDR4 SDRAM
Voltage: 1.2 Volts
Manufacturer: Other World Computing
Country of Origin: Taiwan
Date First Available: April 3, 2019
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Friday, Jul 4
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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- Affirm Financing
- Afterpay Financing
- PayTomorrow Financing
- Financing through Apple Pay
Learn more about financing & leasing here.
Top Amazon Reviews
Size: 16gb
Color: 2 x 8GB
Upgrading my 2019 27" iMac to 32GB of RAM was a fast and a painless effort. The entire process was less than 5 minutes. The computer booted right up and worked perfectly.
Reviewed in the United States on January 28, 2025 by Korley J.
Size: 16gb
Color: 2 x 8GB
I am pleased with OWC for offering great instructional videos and the tools needed to install, and also very pleased with this purchase through Amazon which made an exchange very hassle-free. First set of memory modules were installed properly but found to be defective, leading to successive macOS kernel panics/crashes on my device (I ran Apple diagnostics which did not detect anything abnormal). Amazon initially directed me to the OWC customer site for troubleshooting, but I went with a product exchange through Amazon instead and it was shipped next day. After swapping out the modules for a different set, all is working perfectly. Thank you Amazon and OWC.
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Reviewed in the United States on March 4, 2025 by Mike Eoloff
Size: 64gb
Color: 2 x 32GB
Excellent product Mac desktop 2019
Reviewed in the United States on March 4, 2025 by Jimmy ameca Jimmy ameca
Size: 32gb
Color: (2 x 16GB )
Followed the video instructions for installing in a 2019 iMac 27”. It was a breeze and the new memory was recognized right away.
Reviewed in the United States on March 22, 2025 by don
Size: 32gb
Color: 4 x 8GB
Imac 2019 5k here. 8 Gb out of factory from 2x4 ram sticks. I tend to have a lot of things opened at the same time, but nothing out of the ordinary, a few chrome tabs, a few safari windows , WhatsApp, mail... It was ok with 8Gb but not lighting speed. I was getting the color wheel when trying to open a new tab sometimes. I Wasn't sure how much ram to get from Amazon but the cheapest approach was to do 4x8 since I dont do video editing or anything crazy, I didn't thing anything over 32 would be useful. Install: So they tell you to lay the Mac flat, which I didn't do. I installed the new ram with the iMac vertical: I removed the old old and put the 4 new ones in place I closed the memory compartment and the Mac wouldn't boot a few times I thought I installed them correctly but YOU HAVE TO MAKE SURE EACH IS FULLY, FULLY, FULLY in. A slight off position and your computer won't boot. After trial #3, the Mac booted no problem. Back to were I left when I turned it off prior to ram upgrade. I am now using about 10gb of Ram out of the 32 available but the Mac monitor, with the same apps opened as prior. The difference is night and day when I do something, wether it is a webpage or opening iPhotos or pages, it is just instant. At $150 , it is overall a cheap upgrade given how much money we put in our machines. Super happy with the purchase given the amount of time I spend on the computer, I appreciate the smoothness.
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Reviewed in the United States on July 11, 2020 by gilberg nicolas gilberg nicolas
Size: 16gb
Color: 2 x 8GB
Mu purchase of 16 GB (2x8 GB sticks) of DDR 4 2666 ghz ram went smooth all of the way. It was delivered on time and very easy to install in my 2020 iMac 27". I figured I only needed 16 GB based on my Apple computer Activity Monitor assessment but decided I would try to add it to the existing 2x4 GB sticks I had. For the un-initiated: This computer uses 2 channels for ram. These both must be used or the effect will be decreased random access memory **availability**. There are 4 (four) slots for ram sticks. Channel A is slot 1 and 2, Channel B is slots 3 and 4. To work optimally, so I was led to understand by YouTube videos, the must carry the same amount. To illustrate, I now have 8 + 4 in Channel A and 8 + 4 in Channel B. If I had put this in any other configuration it would not work the same nor would it be optimal. In summary, I now have more than enough ram (there was no availability of 8 GB (2 x4 sticks). It was a bit more expensive than I had seen a year ago but that is life, I guess, you snooze you lose :^)
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Reviewed in the United States on October 21, 2022 by Peter A. White
Size: 16gb
Color: 2 x 8GB
Did not work in 2018 mac mini with MacOS Sequoia - I bought four of these dual 8GB packs to upgrade some 2018 Mac Mini's running Sequoia and all of them had kernel panics. They made the Macs reboot over and over. All of these Mac's had a fresh new install of the OS and no other software installed. I had to return all of the modules because they did not work.
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Reviewed in the United States on March 19, 2025 by Amazon Customer
Size: 64 GB
Color: ( 4 x 16GB )
Works well...seamless installation.
Reviewed in the United States on February 25, 2024 by JGRJR