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Memory upgrade troubleshooting in 2020 27-inch iMacs

wilberforce said:
I believe the iMac 20,2 are those with the 5700XT GPU (or 5700 GPU?). Don't know why, maybe the logic board is different to accommodate the different GPU.
It's not as if 20,2 is a later version of 20,1 as they both came out the same time.
I may be wrong, which would be proven if someone has a 5700XT GPU and their model identifier is not 20,2.
Click to expand...
10- core w/5700xt here and shows iMac20,2 in System Report.
 
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I installed 4 X 32 exact amtching sims from OWC macsales and they are running 2666 and dual channel. I asked then to be sure i got 4 exact sims and they did.
 
wilberforce said:
I believe the iMac 20,2 are those with the 5700XT GPU (or 5700 GPU?). Don't know why, maybe the logic board is different to accommodate the different GPU.
It's not as if 20,2 is a later version of 20,1 as they both came out the same time.
I may be wrong, which would be proven if someone has a 5700XT GPU and their model identifier is not 20,2.
Click to expand...
I see. This was the first time I had seen those designations so I thought they may have indicated some change in design, ie the "old" 2019 iMacs issued in 2020 vs. the "new" 2020 iMacs issued in 2020. Thanks for the clarification!
 
I received my 32GB RAM from OWC. Just want to double check before I install - I remove the 16GB that came in the computer and install the new in the same slots?

I will say that with the 16GB I'm surprised I've gotten the beach ball several times along with a low resource warning. I'm wondering if that is because it has more cores (8) than any other device I've owned.
 
victry1 said:
I will say that with the 16GB I'm surprised I've gotten the beach ball several times along with a low resource warning. I'm wondering if that is because it has more cores (8) than any other device I've owned.
Click to expand...
No. Something you use just takes a lot of memory.
[automerge]1600262318[/automerge]
victry1 said:
I received my 32GB RAM from OWC. Just want to double check before I install - I remove the 16GB that came in the computer and install the new in the same slots?
Click to expand...
Yes.
 
pldelisle said:
No. Something you use just takes a lot of memory.
[automerge]1600262318[/automerge]

Yes.
Click to expand...

Thank you, pdlelisle. I wasn't running anything that is a resource hog which is why I noticed, but, hopefully with the new RAM I won't see that anymore. After reading more in this thread I'm kind of wishing I ordered 64GB but things are tight around here at the moment so 32GB will have to do.
 
victry1 said:
Thank you, pdlelisle. I wasn't running anything that is a resource hog which is why I noticed, but, hopefully with the new RAM I won't see that anymore. After reading more in this thread I'm kind of wishing I ordered 64GB but things are tight around here at the moment so 32GB will have to do.
Click to expand...
If you ordered 16x2, you can always order another pair later.
 
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victry1 said:
I received my 32GB RAM from OWC. Just want to double check before I install - I remove the 16GB that came in the computer and install the new in the same slots?

I will say that with the 16GB I'm surprised I've gotten the beach ball several times along with a low resource warning. I'm wondering if that is because it has more cores (8) than any other device I've owned.
Click to expand...
Forgive me for not reading prior pages if this has been addressed, but the stock 2020 iMac comes with 8 GB (2 x 4 GB), not 16 GB. I would expect a lot of beachballs with only stock 8 GB RAM.
 
victry1 said:
unfortunately, I ordered it with the 16gb before I knew I would have to discard them In order to increase theRAM.
Click to expand...
I’m not so sure. Apple uses Micron. Micron is also one of OWC’s vendors. If the pair of 16s you ordered won’t give you the performance you require, why can’t you return and order a pair directly from Crucial, Micron’s retail arm? Did you buy from someone who doesn’t accept returns?

The T2 chip doesn’t register the sticker on the RAM sticks. As long as all 4 sticks are the same size and meet the spec required by the 2020, you should be good.

We have learned that much RAM that works perfectly well in the 2019 doesn’t mix well when combined with the OE Micron RAM in the 2020.

If I decide to upgrade my 2020 with another pair of 16GB sticks and they don’t match perfectly in all respects, the first pair goes back under the OWC warranty.

This has happened before. I don’t recall how many years ago but a MacOS upgrade gave errors in a whole lot of MacBooks that had upgraded RAM. Fortunately, I’d bought all of it from OWC and they overnighted replacement sticks to me. We’re talking over 100 MacBooks that belonged to a school district.
 
When I added a pair of 16GB Crucial RAM to my friend's new 2020 iMac, the "Memory Slots" in the System Report said the manufacture was “859B”. And the manufacturer of the original 8GB of Apple RAM was “Micron”.

Memory Config.jpg

FWIW i have the same 32GB of Crucial RAM in my 2018 Mini and it too shows a manufacturer of “859B” not Micron.

GetRealBro
 
Hello,

I'm still waiting for my own DIY memories. This will be 64 GB. Currently 8 GB.
However, I diminish the current test result.

iMac 20.2 (i7 3.8 GHz 8 core, currently default 8 GB RAM, GPU 5700 XT)

Single-core: 1270
Multi-Core: 7566

Is the multi result not low or normal?
(After the memory upgrade I'll post my new test result.)
 
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AZREOSpecialist said:
You shouldn't be beach-balling with 16 GB. Were you processing a really large file in Photoshop or something?
Click to expand...

I had 2-3 programs open, probably Lightroom, not PS. Nothing really a resource hog. Fortunately, it doesn't spin really long but I don't think it should spin at all. My 2015 MBP doesn't do that. :( Hopefully, it will improve once I add more RAM.
 
fullhd said:
Hello,

I'm still waiting for my own DIY memories. This will be 64 GB. Currently 8 GB.
However, I diminish the current test result.

iMac 20.2 (i7 3.8 GHz 8 core, currently default 8 GB RAM, GPU 5700 XT)

Single-core: 1270
Multi-Core: 7566

Is the multi result not low or normal?
Click to expand...

That looks "normal" in that it is consistent with scores others report for i7 with only 8GB RAM.
However you should get about 8900 multi-core when you have 64GB.
See:
(you have to click on individual results to see amount of RAM)
 
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I dl Geekbench today and this is the score with 16GB of RAM. I will do another once I install the new RAM. I don't know if this is a good score or not.
Screen Shot 2020-09-16 at 5.24.56 PM.png
 
gtosnipey said:
Just installed OWC 32GB and I also get 2133mhz when leaving in the Apple ram. So what is everyone’s final decision who isn’t buying new ram? My assumption is it’s better to have 40gb at 2133 than just the 32GB at 2666 and putting the Apple memory in a drawer. Thoughts?
Click to expand...

From the gaming benchmarks I've seen it takes a significant memory speed difference to see ANY performance difference even in extremely demanding applications. At a guess you are going to be better off with more memory at a very slightly reduced speed. But as others have mentioned, it's a big "depends on." If you really aren't using more than the 32, you might as well just stick with that at 2666.
 
panjandrum said:
From the gaming benchmarks I've seen it takes a significant memory speed difference to see ANY performance difference even in extremely demanding applications. At a guess you are going to be better off with more memory at a very slightly reduced speed. But as others have mentioned, it's a big "depends on." If you really aren't using more than the 32, you might as well just stick with that at 2666.
Click to expand...
Also see post #409, and post #422, as another data point
 
I just installed my memory upgrade.
System: iMac 20.2 (i7 3.8 GHz 8 core, GPU 5700 XT)

I bought Kingston memory which is system specific memory for iMac 2020.
64 GB RAM (4 x 16 GB) [Kingston - KCP426SD8/16]
Kingston System Specific Memory for iMac 2020

My test result with default 8 GB:
8GB.png


Novabench RAM test with 8 GB:
RAMTEST_8GB.png



My test result with 64 GB (DIY):
64GB.png


Novabench RAM test with 64 GB:
RAM.png


Anyway, this is also worth looking into if you haven’t decided on RAM yet.
Best combination of memory for the 2020 iMac
 
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