64GB OWC Memory Upgrade Kit
only $119.99 $94.75 Limited supply! Only 4 available.

64GB OWC Memory Upgrade Kit

2 x 32GB PC21300 DDR4 2666MHz SO-DIMMs for Mac mini (2018), iMac (2017 - 2020), and compatible PCs

Used | OWC Tested


Mfr P/N: 2666DDR4S64U OWC SKU: OWU2666DDR4S64U

Memory Built by Mac People, for Mac People (and PC too), for Over 30 Years

availabilityIn Stock: Ships Same Day!
$119.99
$94.75
You Save $25.24
Limited supply! Only 4 available.
Add to Cart

More Options

8GB Modules

8GB
arrow up 1 x 8GB $89.99$9.75 in stockIn Stock: Ships Same Day!

16GB Modules

32GB
arrow up 2 x 16GB $59.99$40.75 in stockIn Stock: Ships Same Day!

32GB Modules

64GB
arrow up 2 x 32GB $119.99$94.75 in stockIn Stock: Ships Same Day!

Overview

OWC Memory for Mac & PC

OWC Memory. Built for Macs + PCs.

Experience your computer's true performance potential.

Improve System Speed

OWC Memory is the most cost effective and simple DIY upgrade you can install to unleash your Mac or PC's full potential, and speed up overall responsiveness.

More Apps. More Files

Become a multi-tasking maven when you upgrade your Mac or PC with OWC Memory. Open more apps. Open larger files. Plus, work with multiple files all at the same time.

Save $$ vs Factory

Save BIG vs factory memory options. Plus, select among options not offered by the factory. OWC makes it easy to find the perfect upgrade to fit your needs.

Lab Tested Compatibility

We test every OWC memory module at our in-house lab so you can upgrade with the confidence that your memory is built-to-last.

Lifetime Warranty

We built your OWC Memory upgrade to meet or exceed the toughest industry specs to provide years of worry-free service.

Step-by-Step Videos

Our detailed install videos guide your upgrade from start to finish. We provide all the steps to make your OWC Memory upgrade DIY easy.

OWC Logo

Experience the OWC Difference

Rely on the trusted name for memory upgrades, drives and accessories for over 30 years. Your OWC Memory upgrade was built by Mac and PC people, for Mac and PC people. Our expert support team is always a call or click away. You can talk to an actual human who will kindly provide advice and guidance for any questions you may have.

Being helpful and treating others the way you would want to be treated is not just a novel idea. It’s how we do business. It's how we’re built. It's what we’ve been doing since 1988.

IncludesIncludes

Back to top
  • (2) 32GB PC21300 2666MHz DDR4 SO-DIMM memory modules
  • 2 Year OWC Limited Warranty

    Data Rate

    • 2666MT/s

    I/O Clock Speed

    • 1333MHz

    Registration

    • Non-registered

    Error Correction

    • Non-ECC

    Cycle Time

    • 0.75 ns

    Form Factor

    • SO-DIMM

    Type of Memory

    • DDR4

    PC Speed

    • 21300

    Timing

    • CAS = 18.0
    • Full Parameters: 18-18-18-14

    Bandwidth

    • 21.3GB/s

    JEDEC

    • Fully compliant with JEDEC specifications

    Total Capacity

    • 64GB

    Pin Count

    • 260-pin

    Printed Circuit Board Type

    • Low noise 8-layer PCB

    RoHS Compliant

    • Yes

    Ambient Temperature

    • Operating: 32°F to 185°F (0°C to 85°C)
    1. PC4-21300 DDR4 2666MHz SO-DIMMs will operate at 2400MHz speeds in iMac19,2 models with 3.6GHz Quad-Core i3 Processor. This memory will operate at full 2666MHz speeds in other iMac19,2 models.

    4.9 out of 5

    468 out of 489 (95%) reviewers would recommend this product

    Write a Review
    94%
    3%
    2%
    1%
    0%

    Easy experience all the way through; worked perfectly!

    Everything about this experience was easy: finding the specific cards I needed for my 2020 iMac, ordering them, receiving them (they arrived even earlier than the original ETA), and installing them using the helpful and easy video provided. The only thing I would say to add to the video is to encourage waiting an extra minute or two once the new cards are installed after booting up your Mac for the first time - there was a delay for me and at first I thought I had installed the cards wrong. But it turned out all I had to do was wait an extra minute on the first boot-up afterward. Really great experience! Highly recommended.

    I would recommend this product to a friend!

    Verified Purchase
    Verified PurchaseVerified Purchase.
    trjonas1, 
    • Reviewer:trjonas1
    Response from OWC, Support

    Thank you so much for your amazing 5-star review! We're thrilled to hear that your experience was seamless from start to finish. It's fantastic that you found the cards you needed for your iMac quickly and that they arrived ahead of schedule! We appreciate your feedback about the installation video, and we'll definitely consider your suggestion regarding the boot-up delay. Your insights help us improve and ensure others have a great experience too. Thanks for being a valued customer!


    128 GB worked. Didn't have to find another vendor.

    I purchased 128 GB from Macsales.com a few years ago and it crashed my Mac a lot. When I two sticks out, it worked. I looked for reviews and this was a common issue from this vendor due to low quality ram and people suggested going to Crucial for memory. I recently had a real need to upgrade from 64 to 128 GB and couldn't find the ram from Crucial and decided to give macsales.com another chance. Memory arrived, I installed it and had no crashes in 2 weeks. I made sure I was using close to all that memory by starting up many virtual machines. It worked great.

    I would recommend this product to a friend!

    Verified Purchase
    Verified PurchaseVerified Purchase.
    Reviewer200356250, 
    • Reviewer:Reviewer200356250
    Response from OWC, Support

    We’re absolutely thrilled to hear about your positive experience with our 128 GB memory! Thank you for giving us another chance and for sharing your journey. It's fantastic to know that the memory has been working smoothly for you with no crashes. We pride ourselves on providing high-quality products, and your feedback reassures us that we're on the right track. Enjoy your upgraded performance, and we look forward to helping you with any future upgrades!


    Good upgrade for 2019 27" iMac

    My 2019 27" iMac was running extremely slow, especially after upgrading to macOS Sequoia. While upgrading the memory helped, the computer is still slow opening some apps. I have read other reviews that suggest that the 1TB Fusion Drive may be part of the problem, and that installing an external Thunderbolt SSD boot drive may help; however, I'm not sure if I want to spend more money on a 7-year old computer. I will evaluate over next few months.

    I would recommend this product to a friend!

    Verified Purchase
    Verified PurchaseVerified Purchase.
    Reviewer3195472596, 
    • Reviewer:Reviewer3195472596
    Response from OWC, Support

    Thank you for sharing your experience with your 2019 27" iMac! We're thrilled to hear that the memory upgrade made a positive impact. It’s awesome to see customers like you actively seeking ways to enhance their machines! We totally understand your hesitation about investing more in an older computer. If you decide to explore the Thunderbolt SSD boot drive option in the future, we’re here to help with any questions or guidance you might need. Your feedback is invaluable, and we appreciate you taking the time to share it with us! Please feel free to contact us if you have any further questions, comments, or concerns.  https://eshop.macsales.com/Service/


    View More Reviews
    This item has been added to your cart