Review on Timetec 32GB Kit (2x16GB) Apple DDR4 RAM 2666MHz / 2667MHz for Mid 2020 iMac (20,1/20,2) / Mid 2019 iMac (19,1) 27-inch Retina 5K, Late 2018 Mac Mini (8,1) PC4-21333 /PC4-21300 MAC RAM by Darin Schaffer

I've been using RAM on my new 2020 27" iMac (iMac20.1) 3.3GHz 6- Core Intel Core i5. This memory chip has two problems: 1) it is NOT compatible with Apple's preinstalled RAM and 2) the machine freezes from time to time even if there is a lot of memory. 1) Incompatibility with preinstalled Apple RAM. A: I bought my iMac with 8GB RAM, so it came preinstalled with 2 x 4GB modules (at 2667MHz). I installed TimeTec 2 x 16GB RAM in slot 1 and slot 3, as you can see on my first picture the speed is greatly reduced to 2133MHz. Youtuber Max Tech pointed out this issue and now I removed the Apple RAM and put it in slots 1 and 2 and TimeTec RAM in slots 3 and 4. In the second screenshot you can see that the speed has increased. again at 2667 MHz. And here's the catch. While this scheme is faster, it actually performs worse because it doesn't take advantage of the dual nature of memory cards. The general consensus is that you should put the same memory in odd (slots 1 and 3) or even (slots 2 and 4) numbered slots. In other words, you need to install a pair with different channel numbers and the same DIMM numbers (as you can see on my first screenshot). I have tested various configurations with GeekBench results and found that the first configuration (16/4/16/4) has higher performance scores than alternative circuits such as (4/4/16 /16) or ( 16/16/4/4). Now here is the dilemma. To get better performance, you'll have to settle for a lower clock speed. If you want to keep the original higher clock rate (2667 MHz), you have to give up the dual nature (even worse). What I did was ditch the original 2 x 4GB RAM from Apple and just use 2 x 16GB Timetec RAM in slot 2 and slot 4 (0/16/0/16). This way I avoid the incompatibility issue between TimeTec RAM and Apple RAM, allowing me to keep the original 2667MHz speed and still take advantage of the dual nature by changing the RAM layout (see third and fourth images). But it's a bit inefficient because I'm wasting original Apple RAM. 2) random beach balls and hangers. The big problem with this RAM is that it looks like it hasn't been thoroughly tested as to whether or not it's compatible with my iMac 27' computer. I've been using TImeTec RAM for 2 months now and I often get beach balls and freezes (about a couple of times an hour) even when I'm not doing anything intense. They mostly go away within a few seconds, so I'm not too worried about usability, but they're annoying nonetheless. These freezes occur even when I'm watching Netflix or Hbo Max (which never happened on my very old 2015 Macbook Pro). So I'm really confused as to why the new 2020 iMac has trouble watching Netflix/hbo when my 2015 Mcbook Pro has no trouble. I think it has something to do with that incompatible RAM, which is disappointing. Summary: It's too late for me to return these RAMs, but I think I might actually go back from the 2 x 16GB to my original Apple 2 x 4GB RAM if these random freezes continue. I wish the company that sells this RAM would test them more thoroughly before selling them and explain all of these issues more clearly before I discovered them myself. In the end I feel my money was wasted and that's why I give them 1 star.