16GB (2 x 8GB) DDR4 2666MHz PC4-21300 260-PIN SODIMM MEMORY RAM KIT COMPATIBLE WITH 27" RETINA 5K IMAC (2019/2020)

Ordered on the 27th July and paid £10 extra for postage to ensure next day delivery, which was well worth it (based on an experience of ordering from another highly rated company a few days earlier, who then fulfilled it from Amazon US. After 7 days an opened, empty bubble wrap bag was delivered through my door so the contents went missing somewhere between Texas and Nottinghamshire. Amazon were good though in arranging a refund quickly, so thanks Amazon).The new cards were well packed and delivered by Royal Mail the next day. Purchased for a 2020 (Model Mac 20,1) to add to the 2 x 4Gb cards already installed. They are working perfectly and all cards are operating at the expected 2667 MHz. Based on my overall experience I would certainly use this provider again.THE FOLLOWING INFORMATION IS FOR USERS OF iMac MODELS LIKE MINE AND WILL HOPEFULLY SAVE TIME WITH CARD CONFIGURATIONS WHEN INSTALLING PAIRS OF CARDS WITH DIFFERENT MEMORY CAPACITY.I am adding 2 x 8Gb cards to the existing 2 x 4Gb cards already installed. The RAM port at the back of the iMac is easy to remove. I have added the cards into the 4 slots as per the attached image. This gives the expected 2667MHz speed across all 4 cards, despite the channels being asymmetrical in total memory (channel A has 16Gb whereas channel B has 8Gb). Trying to make the channels run symmetrically (i.e. an 8Gb & 4Gb card in slots 1 & 2 with the same in slots 3 & 4) brings down the speed from 2667MHz to 2133MHz across all 4 cards - grouping the two 8 GB sticks into Channel A (as per the image) and the two 4 GB sticks into Channel B keeps the physical serial lines uniform per channel. This tricks the motherboard into running at full native 2667 MHz bandwidth. Whilst technically asymmetrical in absolute dual-channel maths, multiple real-world iMac benchmark tests on MacRumors and Apple Forums prove that having your RAM run at its full 2667 MHz speed gives a much better overall performance boost than dropping down to 2133 MHz just to have a perfectly symmetric channel balance. With this configuration up and running I can already see that the photo-editing software I am using is already running much more quickly, and with the iMac opening apps, screens and running video etc much more quickly. I hope this helps someone (and saves then the several hours of research, plus there trial and error testing that I underwent).

Fitted this RAM in a 2019 iMac, this is the first time I had done it, worked perfectly and the machine is running a lot faster now. I would definitely recommend the seller, the RAM arrived well packaged and on time. Hopefully will give my machine another couple of years life.

Excellent outcome and so easy to use

Item arrived promptly and was well packaged. Excellent description made the purchase worry free.

Satisfecho con la compra. Evidentemente la memoria se instala rápidamente, y el iMac funciona perfectamente.

Mijn Mac is nu een stuk sneller.