Chosen Solution
I have an iMac Retina 5K, 27-inch, 2019 with 2 x 4Gb DDR4 a 2667 MHz and it is very slow on some tasks. I would like to install max RAM and I need some confirmation. This product has 4 slots so the max RAM should be 4 x 32Gb = 128Gb, is it correct? I would like to buy 2 x 32 Gb at first and then the other 2 x 32Gb just in case I need it. My second question is: can the configuration 2 x 32 Gb + 2 x 4 Gb works? And finally; can I buy 3200 MT/s for my iMac? I know it will automatically switch off at 26667 in case I use it with the current 4Gb at 2667; but just in case can I buy it or I have to buy the 2666MT/s? I would like to buy this Crucial CT2K32G4DFD8266 Kit 64 GB (32 GB x 2), DDR4, 3200 MT/s, DIMM, 1.2 V, CL19. Thanks :D
@uncoke Hold on here! A slow system sounds like there is something more going on. While 8 GB is on the low end unless you have a lot open at the same time it should be OK. Do keep in mind when the system needs more RAM it leverages your drives space (Virtual RAM) to make up the difference. So that means your drive needs attention as well. As far as going so large unless you’re doing deep music/video editing or large image work illustration or photography or always having 30 or so web pages open at the same time going any higher that 32 GB is a waste! I would also stick with what the system requires 2666 MHz PC4-21300 DDR4 SDRAM SO-DIMMs (260-pin).
You can use higher speed ram no problem. It will just run slower. You can mix and match ram however you want. 40GB will work too although it wont make much of a difference. Wish you luck!
