OWC 16GB (2 x 8GB) PC14900 DDR3 1866MHz SO-DIMMs Memory Compatible with 2015 (Late) iMac 27" w/Retina 5K Models and Compatible PCs

Read the reviews, and bought the OWC memory for my late 2015 27" iMac, installed them along with the original 2 x 4Gb, so giving me 24Gb of memory, apart from installing into the slots only to find I had 2 x 4 on one side and 2 x 8 on the other, but once installed in the correct slots, got the 2 x 8 on the bottom and the 2 x 4 on the top row. I looked at the Kingston memory for the same spec. and it was nearly double the price,. The OWC was seen straight away on start up, and works fine, working on Final Cut is much easier and quicker, would recommend this product.

Works like a charm.***update***After a couple of days my iMac 5K with exact same specs on original ram started freezing and restarting itself. I recorded a video of this happening. With the restart there is a very bad noisy sound coming from speakers. I will try to return the 16 gb of ram because I’m afraid of damaging computer. I will keep you posted if the reversal transaction is going to effect.**update2**Returned due to crashing my iMac 5K late 2015. Money refunded.

Memory upgrade for iMac, instant responsiveness. Word of warning put them in alternate to original ram or you will get a blank screen!! ( bottom original next new ram then original top new ram) hope this is helpful.

Arrived the next day. I installed the RAM and my iMac appears to be operating faster and more smoothly. Very happy.One observation. Accessing and installing the RAM is very clear on the Apple site. My iMac had the original two 4Gb sticks. When installing the two new 8Gb sticks, It took several attempts to work out which slots to use. There is contradictory advice online. Anyhow, I got there in the end as there are not that many possibilities. My machine booted up is now running with 24Gb of RAM.

This product was clearly referenced as to being suitable for my particular computer, even down to the manufacturers month and year.Robustly packed with all the information required to install.Very easy to install.Long manufacturers guarantee.Immediate self setup and check. Very happy with the entire purchase.

I upgraded from 8GB to 32GB on a 2015 iMac - easy to install and worked perfectly straight away. Made a big difference to stability running multiple simultaneous programs. Excellent value for money compared to the cost of the same memory capacity purchased from Apple. On a new iMac I would not hesitate to get minimal RAM fitted as standard and upgrade with OWC products.

Am now the proud owner of a 24gb / 2 tb hd 27"iMac with 5k Retina . Albeit going on 6 years old this machine still has years of life in it. Much more sustainable than replacing it and much more affordable to get the memory installed than to buy the Mac new with all that memory.

A straight forward upgrade for my late 2015 iMac 5K 27” iMac. Simple to install and a noticeable improvement in performance.