2019 Imac 27 3.7 - Memory add caused crashing "

[GPD-AZ]

I have a 2019 27" 3.7 iMAC. I bought it with 8 gig onboard.

I purchased the recommended OWC 16 x 2 DDR4s.

1. When I added the 16g to each of the available slots (and expected 40G), the machine would not boot.
2. I removed the 2 4G and replaced each with a 16. Machine booted fine. Memory showed OK in diagnostics. Performed well.

Each time the iMAC slept or even went to screen saver, it would crash and reboot. I called Apple support and went through the safe boot process and did a bunch of "delete app, install app" and "log out/login" stuff. Problem did not go away.

This morning, I removed the 32G and put the 8G back in. Problem gone.

Thoughts? Thanks!

OWC 32GB (16GBx2) DDR4-2666 Kit

 

[whosthis]

Thoughts? Thanks!

OWC 32GB (16GBx2) DDR4-2666 Kit

Return them. They seem to be faulty. Unfortunately, I've read this more than once on the forum here for OWC memory. They are great at marketing. Quality - not so much.

If you can get a refund, I'd take it and get modules from a manufacturer. Not some dubiously rebranded and recolored ones.

 

[GPD-AZ]

Roger that and thanks for the validation. Good news is I bought through Amazon and return is no problem. I'm sure there are dozens of threads on preferred memory. Crucial? Other?

 

[whosthis]

I am happy with my Samsung, but others may be fine, too. Look around on this board, there are a couple of threads discussing this.

 

[28Gauge]

I ordered Crucial 16GB x2 RAM from Amazon for my 2019 i9 iMac. No issues at all after installation.

 

[GPD-AZ]

Thanks! I RMA'd the memory and bought some new. I'll see how that works on Saturday. I appreciate the community!

 

[Rumpot]

Thanks! I RMA'd the memory and bought some new. I'll see how that works on Saturday. I appreciate the community!

I had the same issue with the recommended OWC 16 x 2.
Found out it didn't like not being in the same bank, so I placed them together and it been working great.
i.e. view from the back
--owc16
--apple4
--owc16
--apple4
This configuration did not work for me and I got the same symptoms as you.
If I used either the stock apple ram or just the owc it worked great
Switched to this
--owc16
--owc16
--apple4
--apple4
and this is working for me for all 40GB