27" iMac 2019 - 64gb RAM Installation Questions

[gloamstur]

I recently purchased 2x32gb RAM chips from OWC for my 2019 27" iMac with i9. I removed the original Mac RAM (2x4gb) and installed the OWC RAM only. I was not able to boot the computer when placing the OWC RAM in the same slots the Mac RAM(1 & 3) inhabited. I was able to boot the computer when I placed the OWC RAM in the previously unused slots (2 & 4). I am now efficiently running (I think) 64gb of RAM in the 2 & 4 slots.

Questions:

1. After installing the new RAM, running the computer, shutting computer down for the night, starting computer in morning, running computer, and then randomly restarting the computer - the iMAC took about 15 minutes to reboot. Is this normal behavior with new memory installation? It was the first time I "officially" restarted since installation. I wasn't installing any upgrades or a new OS. Just curious if anyone has had this experience with memory installation.

2. Is it normal for RAM to correctly work in the 2 & 4 slots instead of the 1 & 3? I didn't do much experimenting and immediately placed the OWC RAM in the 2 & 4 after it didn't work in the 1 & 3. Any insight closely explaining this dynamic is appreciated!


-Happy Holidays.

 

[wilberforce]

Edit: Nevermind, I just realized you are referring to 2019 iMac, not 2020 iMac

 

[mdgm]

Have you tried doing PRAM and SMC Resets?

More memory does increase boot times but it should be nothing like how long it’s taking for you.

 

[gloamstur]

Have you tried doing PRAM and SMC Resets?

More memory does increase boot times but it should be nothing like how long it’s taking for you.

Thanks for the response.

My lagged boot time was a one time deal. I essentially installed the memory one day, worked on the computer (with new memory), shut it down, started computer next day, did a restart - and that's when I had the lagged boot time.

This is probably a minor issue if one at all. I'm mostly curious if the lagged boot was the iMac processing the new memory and getting everything situated. I wasn't doing any other updates at the time.

Edit: Nevermind, I just re

Have you tried doing PRAM and SMC Resets?

More memory does increase boot times but it should be nothing like how long it’s taking for you.

alized you are referring to 2019 iMac, not 2020 iMac

No problem

Have you tried doing PRAM and SMC Resets?

More memory does increase boot times but it should be nothing like how long it’s taking for you.

I have not done a PRAM or SMC reset. Do you think these would be a good idea? Even just for routine maintenance? I did run a Novabench Test and received a RAM score of 359 with 28281 MB/s speed.

 

[mdgm]

Ah, one time it would sound like it was doing something one off. If not experiencing any issues sounds like it’s fine.