OWC 8GB (2 x 4GB) 1866MHz DDR3 SO-DIMM PC3-14900 204 Pin SO-DIMM CL13 Memory RAM Upgrade Module for 2015 iMac 5K 17,1 (OWC1867DDR3S08S)

I recently upgraded my 27-inch iMac (Late 2015 model) with the OWC 32GB (4 x 8GB) PC14900 DDR3 1866MHz SO-DIMMs, and I couldn’t be happier with the results.The installation was a breeze. Even for someone who doesn’t tinker with hardware often, the process was straightforward, thanks to OWC’s design and compatibility. Within minutes, I had all four sticks installed, and my iMac recognized the full 32GB of RAM without a hitch.The difference in performance is night and day. My machine, which was beginning to show its age, now feels incredibly snappy and responsive. Multitasking is effortless, with no lag even when running resource-intensive applications like Photoshop or Final Cut Pro. It’s like breathing new life into my iMac without having to shell out for a new computer.If you’re using a Late 2015 iMac and want a significant performance boost, I highly recommend this OWC RAM upgrade. It’s a cost-effective and easy solution to keep your system running smoothly for years to come.

Everyone with an Intel iMac should be running 32Gb Ram…

Worked perfectly in my iMac (late 2015). No compatibility issues. Easy to install and great memory quality. No issues with freezing or lag. My mac is running like new again!

I upgraded a 27" Late-2015 iMac from original 8GB (2 x 4GB RAM) to 32GB (4 x 8GB RAM). The computer is now fast again. No latency or maxed out memory resources. I can run multiple apps at one time again without the computer stopping or forcing to quit an app that is not responding due to memory conflict.These OWC cards are perfect for this application. Install took just a couple minutes. Should have done this long ago. I have effectively a new iMac for less than $75.

In early 2016 I bought my late 2015 iMac 27" Retina 5K with 8GB and a standard HDD. It was super fast running macOS Sierra, High Sierra, and Mojave. Then when I upgraded to Catalina, it went from flying to crawling. I suffered with it for years. Then recently I read something that suggested I needed more RAM. As a software engineer for decades, it seemed impossible to me that this iMac couldn't run decently with 8GB since it already had for 3 OS versions. Anyway, I installed two OWC 8GB sticks to give me a total of 24GB and to my delight my iMac has been reborn, now as blazing fast as the day I got it. I have fallen in love again with my big beautiful iMac.I feel very dumb for not doing this years ago, but in my defense, despite my many interactions with Apple Care over the years, not a single tech suggested this simple fix.I'm now running macOS Monterey and it's still super fast.

Note, there are configuration changes needed to install this memory on that NAS model (look online).The memory has worked consistently without issues for over a month of continuous usage.UPDATE:The Synology device started crashing or failing to boot altogether.Nothing inherently wrong with the memory itself, it's just not really compatible with this NAS model.

The support really came through on this purchase for me. I put the RAM in a 2015 iMac 4ghz 395X and soon after started experiencing hard crashes and the machine totally freezing with no crash logs generated. I have noticed several others with this configuration having issues as well. I think this combo must be very finicky when it comes to RAM tolerances.I went through a lot of diagnosis as I recently added multiple thunderbolt peripherals and change my setup a bit. Isolated it down to the memory and worked with support.Went through some more diagnostics with support and they agreed to do a replacement / RMA. Since I have received the replacement RAM have had zero issues and the machine is totally stable.I wasn't planning on using it, but knowing that OWC would provide good support was the main reason I decided to pay the slight premium and get the memory from them. So I would recommend them over other options as this is one area of a build that really makes a difference and you want good support if you run into issues.

I wanted to upgrade my iMac late 2015 5k to a full 16GB of ram with a quality product and that's exactly what I got. Found the ram specifications on the iMac and confirmed those specs with the OWC website. Felt confident with product compatibility. Located a OWC product video and proceeded to install the pair of 4GB ram modules with no problems whatsoever. iMac instantly recognized the install. Very happy with the entire process. I would have no concerns recommending OWC products.