A-Tech 32GB (4x8GB) RAM for Apple iMac Late 2015 27 inch Retina 5K | DDR3L 1866MHz / 1867MHz PC3L-14900 1.35V 204-Pin SODIMM Memory Upgrade Kit

My iMac (model 17,1) was a new release with the highest specs when I bought it in late 2015. I upgraded early on from 8GB to 24GB of RAM through OWC, and that memory has worked great. But I was not looking to spend the same price for RAM at the end of 2020 as I did in late 2015, and for a computer that was five years old. I took a risk on this A-Tech RAM to save 30% on the price of OWC. As the rightmost photo below shows, the RAM passed MemTest (free version) with zero errors. In terms of performance, the RAM increase was just 24GB to 32GB, so only a one-third increase. However, per the second-from-right photo below, the tests show memory pressure about halved from before the new RAM installation (Dec. 24, 2020). The use of compressed memory declined substantially (see third-from-right photo). I did not experience the problem reported by some other reviewers about the RAM not running at full speed. As the leftmost photo below shows, the memory is running at 1867 MHz. If your memory does not run at full speed, make sure that you are pairing the memory modules so that the new modules from A-Tech are paired with each other in your memory slots. My iMac was running fine even with 24GB, so don't expect a major improvement jumping to 32GB. But at least the testing shows a performance improvement. I sense a bit of an everyday speed boost, but it has been slight. With Photos and iMovie, you might see some more benefit.

FANTASTIC! I had to do a little research to make sure I was ordering the right product for my iMac System specs. Double check and Double check. And then after I ordered, I was nervous that the precise product would be shipped. Delivery was prompt. Next, unplug and wait about 30 minutes to let the iMac cool down. Wear plastic gloves to keep any finger oils from contaminating the memory boards and slots. Pull the old boards out. Push and snap the new memory boards in. It took the Activity Monitor about 5 minutes to recognize and monitor the system. Compatibility is spot on. Memory speed is greatly improved. RAM upgrade is wonderful. EVERYTHING IS PERFECT!

In our household we have two iMac 27 inch, late 2015, with 8GB RAM. One has an i5 CPU, and another i7 CPU. They are still performing perfectly, and we never noticed during years of daily use any problem with them. We follow all Apple's upgrades. While comparing response with Macbook Pro having 32GB RAM they are noticeably slower, perhaps the difference is due to the newer i9 CPU and not necessarily only larger RAM. Today RAM memory upgrades are affordable so I bought a 16GB kit (2x8GB) compatible DDR3L 1866MHz non-ECC SO-DIMM. Each operating system upgrade is always more memory hungry, thus more RAM should be beneficial. Now after upgrades one iMac has 2x8GB, and another 4x4GB modules. Thanks to the iMac design, RAM upgrades are very friendly. Everything is working as before, perhaps faster. Difference is not obvious without measurement that I didn't bother with doing. I recommend the product and the seller for excellent service. They send the product promptly and well packed, with a phone helpline, and 100% satisfaction guarantee. Luckily, my upgrades went perfectly smoothly so there was no reason checking if their promises were kept to every letter.

Installed it in my iMac a few weeks ago. It’s worked fine so far.

I only had 8 gigabytes of memory in my apple and all the apps were running slow. My Apple can take 32 Gigabytes and I saw the price and how easy it was to install. The were exactly what they said it was and everything is running so much faster, so I would recommend buying your memory from this vendor.

The delivery was very timely and the instructions received with the RAM was easy to use. Installation was essentially a 5 minute process and the results was exactly as expected. Yes, I definitely recommend this vendor and product based on my personal experience.

Very GOOD MEMORY, AFTER 2 plus years no problems to report

Super easy to install, and greatly improved my MACs processing speed. I have been using them for a few months now and have had zero issues. They work great.

Fui muito bem atendido, o vendedor foi muito correto e entregou os pentes de memória bem antes do prazo combinado. Foi muito fácil instalar os pentes em meu Mac e não houve qualquer problema de compatibilidade. No entanto, recomendo ficar atento às especificações de cada máquina. No meu caso correu tudo bem. (Fiz o dever de casa, li o manual e pesquisei antes de comprar.)

Bang for your buck. Loved it.

Facile à installer dans un Mac 2015.

Very easy to install but make sure you hear the click. The RAM has worked perfectly 5 weeks after installation. Would recommend A-Tech based on my experience and will buy them again for sure.

Item arrived sooner then was originally scheduled. RAM was recognized by iMac once installed. Just wondering why the model and serial numbers are blank compared to existing RAM that came with the iMAC. Is this an issue? Otherwise, seems to work fine at this time.