Samsung 2667 DDR4 PC4 ram

If your iMac is a 2020 model (they came out at the beginning of August, however ALWAYS check About this Mac to verify the model year, this is located under the symbol in the upper left of the display.

Most experienced users on these forums recommend both Crucial.com or Macsales.com RAM. I have a 27" 2020 model and below is the OWC RAM I installed. Be careful if you have a 2020 model and look at which slots I have the RAM installed in and the speed. If you do not follow what I have you will not get the best speed.

When Apple (well Foxconn really) installs the new RAM it is installed in matched pairs, however when it is upgraded if you continue to install in matched pairs this slows down the speed of the RAM. I learned from trial and error.

Thanks; I used to have an article (can't find it any longer) where Apple showed the OEM installed in slots 1 + 3 in the vertical arrangement to "match"; in the even older ones, the match was horizontal. Throughout those slot arrangement changes, they never once adjusted the way the slots are displayed in the "about this mac", so it is difficult to figure out which pairs are matched.

babowa, I believe they are still installed in slots 1 and 3. I purchased a 32GB kit from OWC and had to remove one of Apple's DIMMs and put it in another slot to configure it as rkaufmann87 suggested.

Paul

What model is your iMac? 21.5 or 27"?

OT question: in the brand new models, is the factory installed RAM now in slots 1 + 2 with 3 + 4 empty? Asking because in earlier models, the OEM RAM would be in slots 1 + 3.

I know.

Please navigate to the link below if you have a 2019 or 2020 iMac. This is the correct RAM to buy:

https://eshop.macsales.com/shop/memory/imac-2019-27-inch

Thanks. I don't have a 2020 - mine is a 2017 (and a 21.5" which means you can't get to the RAM anyway).