OWC 16GB (2 x 8GB) PC21300 DDR4 2666MHz 260pin SO-DIMMs Memory Ram Module Compatible with Mac mini 2018, iMac 2019 and up, and Compatible PCs (OWC2666DDR4S16P) TAA Compliant

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.

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.

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 placeI closed the memory compartment and the Mac wouldn't boot a few timesI 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.

Followed the video instructions for installing in a 2019 iMac 27”. It was a breeze and the new memory was recognized right away.

Excellent product Mac desktop 2019

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 :^)

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.

Works well...seamless installation.