I have a 2019 27 inch iMac on order and I ordered it with 8GB of Ram. I want to buy two 32GB sticks and have them ready to install when I get the new computer home. I'd prefer to buy Crucial brand memory but I'm having trouble figuring out which Ram to buy on the Crucial web site. I see 32GB sticks there but one is RDIMM and the other is LRDIMM and I can't figure out which one I should buy. I'm no expert but it looks to me like Crucial could make their products a lot easier to buy. OWC makes this a whole lot easier and I'll be buying from them if I can't figure this out soon. Update: I just had a chat with Randy R at Crucial and he couldn't answer my question because according to Apple the iMac maxes out at 64GB of Ram so the only sticks they can recommend are 16GB. Looks like I'll be buying OWC Ram.