iMac 2020 RAM Recommendation

[Moriarty84]

I know there are several posts about RAM upgrade problems on 27" iMac 2020, but I really wasn't able to figure out a proper course of action based on those. I recently bought a 27" iMac 2020 and installed OWC 16GBx4 RAM cards, removing the factory cards. After just a few days, I had multiple crashes and was unable to even start my iMac. I had it serviced locally (wiped the hard drive and reinstalled MacOS). Before having it serviced, I replaced my RAM upgrade with the two 4GB cards that came in the machine. The service technician said that once the iMac was up and running again, there were no hardware problems showing up on diagnostic tests. I picked up my computer and reinstalled my OWC RAM (16GBx4) only to have immediate, successive crashes when I began using my iMac. I then realized the RAM cards were likely the issue. I have replaced the factory RAM in the same slots they came in and have been running the iMac without a problem.

My questions are:
Is this a problem with the manufacturer (OWC) of the RAM?
Is there a more reliable brand I could try?

I'm not especially proficient in the technical aspects of computers generally, so I'm likely missing many other variables in troubleshooting this. I can't get by on 8GB of RAM but I really don't want to put the OWC cards back in my computer because of how catastrophic the results were.

Any help is appreciated.

 

[rbrick49]

I am running 64 gb of rem on my iMac with no problem but you need to use recommended upgrade memory sticks

 

[IowaLynn]

I know there are several posts about RAM upgrade problems on 27" iMac 2020, but I really wasn't able to figure out a proper course of action based on those. I recently bought a 27" iMac 2020 and installed OWC 16GBx4 RAM cards, removing the factory cards. After just a few days, I had multiple crashes and was unable to even start my iMac. I had it serviced locally (wiped the hard drive and reinstalled MacOS). Before having it serviced, I replaced my RAM upgrade with the two 4GB cards that came in the machine. The service technician said that once the iMac was up and running again, there were no hardware problems showing up on diagnostic tests. I picked up my computer and reinstalled my OWC RAM (16GBx4) only to have immediate, successive crashes when I began using my iMac. I then realized the RAM cards were likely the issue. I have replaced the factory RAM in the same slots they came in and have been running the iMac without a problem.

My questions are:
Is this a problem with the manufacturer (OWC) of the RAM?
Is there a more reliable brand I could try?

I'm not especially proficient in the technical aspects of computers generally, so I'm likely missing many other variables in troubleshooting this. I can't get by on 8GB of RAM but I really don't want to put the OWC cards back in my computer because of how catastrophic the results were.

Any help is appreciated.

#1 Reach out to OWC! Did you use their tool kit and watch their DIY video?

You could try with just 2 memory cards at a time.

OWC us a reseller. Memory might be Samsung, Crucial/Micron and others. You bought direct www.macsales.com for your exact Mac?

When first happened, time to get advanced exchange.

 

[rbrick49]

there is a recommendation page for all the different models just do search for upgrading ram on safari it has all the different models

 

[Moriarty84]

I contacted OWC right away and I'm awaiting their reply. I ordered directly from OWC and have no need for a toolkit. I've installed RAM cards in iMacs before without incident, so I don't think my methods were wanting. I'll see what OWC has to say.

 

[IowaLynn]

Quote:

“I'm not especially proficient in the technical aspects of computers generally, so I'm likely missing many other variables in troubleshooting this.”

 

[jshcy]

I had the exact same issue! OWC exchanged the memory modules and the new ones work just fine without any issues. I just can't believe how widespread this problem is.

 

[DeltaMac]

Perhaps you have one (or more) bad sticks from OWC (It happens)
Have you tried swapping in just one OWC 16 GB stick, then try a few tasks with the idea of doing the same things that would cause a crash?
If all is good with one stick, add another OWC stick, and test again. Continue adding sticks until you have your problem again.
I would probably start by leaving both original sticks in place, until you get two of the OWC sticks that work, then remove BOTH of your original sticks. You would know that the pair of OWC sticks have already tested good, so you could then go to 3 sticks for testing.
If you experience problems after adding an OWC stick, remove THAT stick and try another OWC stick.
You might end up knowing exactly which stick is causing the problem.
(Yes, it's not a fast kind of troubleshooting. You might have to swap several times. Restart with an NVRAM reset each time you change the memory configuration.)

 

[Moriarty84]

@jshcy Thanks. That makes be a bit more hopeful.

 

[wilberforce]

A number of people have had issues with 4 sticks of OWC RAM in the 2020 iMac, see:

Help with 27-inch iMac 2020, i9, 5700XT, 64 GB (Crash and Reboot)

This seems to be another case of 2020 iMac crashing when using 4 sticks of OWC RAM https://forums.macrumors.com/threads/2020-imac-constant-crash-with-128gb-ram.2263538/?post=29197499#post-29197499

forums.macrumors.com

But many others have found OWC RAM is fine, so it appears to be hit or miss.
I suggest return it to OWC and either get a replacement from OWC or change to Crucial.

 

[Moriarty84]

Thanks, everyone. I have been waiting for a reply from OWC since yesterday, but I think I may have to call them to get the ball rolling on a return or replacement.

 

[IowaLynn]

A number of people have had issues with 4 sticks of OWC RAM in the 2020 iMac, see:

Help with 27-inch iMac 2020, i9, 5700XT, 64 GB (Crash and Reboot)

This seems to be another case of 2020 iMac crashing when using 4 sticks of OWC RAM https://forums.macrumors.com/threads/2020-imac-constant-crash-with-128gb-ram.2263538/?post=29197499#post-29197499

forums.macrumors.com

But many others have found OWC RAM is fine, so it appears to be hit or miss.
I suggest return it to OWC and either get a replacement from OWC or change to Crucial.

Bad batch can happen. Mislabelled even.

Did anything change with iMac 2020 that might account for this?

 

[Bryan Bowler]

Nothing has changed as far as I am aware of, but maybe others can offer first-hand experiences. If there is no issue, add as much as you can afford!

 

[Jordan Klein]

I purchased 2 of the Crucial CT2K32G4S266M (2x 32GB) packages from Amazon. They are more expensive than the OWC memory but there are far fewer people reporting problems with it on MR. To be clear, I have a total of 128GB of memory.

So far, I've had no problems with the memory. Even ran a full memtest86 (had to download the beta version so it would boot) and it took about 2 full days but all memory passed testing. That's no guarantee, of course, that there won't be problems, but so far so good!

 

[PBG4 Dude]

I purchased 2 of the Crucial CT2K32G4S266M (2x 32GB) packages from Amazon. They are more expensive than the OWC memory but there are far fewer people reporting problems with it on MR.

So far, I've had no problems with the memory. Even ran a full memtest86 (had to download the beta version so it would boot) and it took about 2 full days but all memory passed testing. That's no guarantee, of course, that there won't be problems, but so far so good!

Been using this RAM since September in my 2020 iMac without issue.

 

[Nicole1980]

Been using this RAM since September in my 2020 iMac without issue.

Yep. Honestly I would just return the faulty ram to OWC and get a refund and try a different manufacturer. I’ve just heard too many stories about issues with their stuff.

They’ve got this big ‘name’ recognition in the Mac universe but I think that’s because they’ve positioned themselves as an entirely Mac centric reseller so us macheads think that makes them better.

I think the time is long overdue to reconsider our assumptions.

 

[IowaLynn]

Memory even from Micron/Crucial was not always a walk in the park when it came to PMG5, ECC, Mac Pro or back when SDRAM lacked SPD code in 1999.

I point out OWC not to buy, but to find what memory modules and spec are recommended and supported by a Mac. Everymac or iFixit might also. And I have seen issues with Crucial. Or people wanting wrongly to install Ballistix.

Building a PC and having to deal with supported specs also can result in swapping sets at times.

 

[Excitable Boy]

Hi All, I'm new here, but a long time Mac user. I've just bought a new mac a 2020 iMac i7 wanted/needed some more RAM but not a bucketload, stock was 8GB.

Very well familiar with how finicky Macs can be with RAM and I've been doing plenty of reading around the net, particularly here. I looked at all the notable makers and their 'Mac' renditions of what appears to be essentially the same RAM (appears). Still can't fathom (after 30+ yrs) why Mac users STILL have to pay a premium for pretty well everything, but unfortunately didn't have the courage for a leap of faith! Done that before and fell on my face!

I wanted a modicum of certainty this time, that it would work after parting with my reddies. But still didn't want to pay through the nose, so I shelled out a modest amount $A99/Module for 32GB (2X16GB) of ADATA ddr4 21300 and it seems to be running fine at the correct speed according to SysProfiler (@2.6Ghz) haven't got any app(s) to test with (yet) but I'll look for some. With a new machine none of my old software will run on this puppy.
I did try installing the original SoDIMMS (Hynix) 2x4GB with the new modules( after testing first without) and it was happy to Start-Up (boot) and recognised all the modules but only wanted to run all modules @ 2.13Ghz. So I'm guessing that to be a manufacturer incompatibility.

Where I'm domiciled, pricewise the ADATA modules were similar price to Kingston,Crucial (Non mac Certified) Samsung (Non mac Certified) There was cheaper stuff and ALL the Mac Certified was significantly dearer by about 30~50%.

So at this stage I'm happy it's working AFAIKS @ spec and without feeling as if I've been ripped off.

 

[wilberforce]

So at this stage I'm happy it's working AFAIKS @ spec and without feeling as if I've been ripped off.

Sounds like it is working well for you.
As one check, I suggest run Novabench RAM speed test. You should get 28,000+ MB/s transfer speed. (Run it several times and use the fastest score).

 

[Excitable Boy]

Sounds like it is working well for you.
As one check, I suggest run Novabench RAM speed test. You should get 28,000+ MB/s transfer speed. (Run it several times and use the fastest score).

Thanks for the tip... I ran Novabench and the average over 4 runs was 27,654.25 with my best run 27,778 and my worst 27,390 So I'm not in the 28,000+ zone but close enough I think/hope.
It's an i7 so it's unlikely to be a top scoring machine the other readings cpu,gpu and disk scores were all extremely close to each other with negligible variation over 4 runs.

 

[SO8]

I've just got a 2020 iMac to compliment the 2010 one which is still going strong. I uprated the Ram to 64GB using Crucial and have had no issues at all.

When I tried to be cheeky and put the standard 8GB in slots 1 and 3 as well as the Crucial 32GB's in 2 and 4 it reduced the speed of the Ram to 2100 ish .... Having looked on the net I saw that using the original in slots 1 & 2 with the new Ram in 3 & 4 should be ok ... and it was, showed all running at the correct 2666 speed. The thing is I did a Geekbench test on the now 72Gb and found it ran slower than the 64Gb on it's own. I am guessing this is due to the position in the slots as the newer Ram is not in slots one apart, and instead next to each other which obviously it doesn't like as much !

The Geekbench score with 72Gb allegedly running at the correct 2666 was 5800 multi core. If I took out the original 2x4 Gb chips and moved the new memory back to slots 2 and 4 it gave me 6800 multi core ... so guess I am staying at 64Gb and no more. That will teach me to be greedy for another 8gb Ram !

 

[PBG4 Dude]

I've just got a 2020 iMac to compliment the 2010 one which is still going strong. I uprated the Ram to 64GB using Crucial and have had no issues at all.

When I tried to be cheeky and put the standard 8GB in slots 1 and 3 as well as the Crucial 32GB's in 2 and 4 it reduced the speed of the Ram to 2100 ish .... Having looked on the net I saw that using the original in slots 1 & 2 with the new Ram in 3 & 4 should be ok ... and it was, showed all running at the correct 2666 speed. The thing is I did a Geekbench test on the now 72Gb and found it ran slower than the 64Gb on it's own. I am guessing this is due to the position in the slots as the newer Ram is not in slots one apart, and instead next to each other which obviously it doesn't like as much !

The Geekbench score with 72Gb allegedly running at the correct 2666 was 5800 multi core. If I took out the original 2x4 Gb chips and moved the new memory back to slots 2 and 4 it gave me 6800 multi core ... so guess I am staying at 64Gb and no more. That will teach me to be greedy for another 8gb Ram !

The following thread goes into the mixed RAM issue in graphic detail:

Memory upgrade troubleshooting in 2020 27-inch iMacs

Hi all! First post on this site. I received my 2020 27" iMac (tier 3 stock configuration) yesterday and have been using it happily since. Today I received some Crucial memory (CT2K8G4S266M aka 2 sticks of 8GB 2666) and I installed it in the two slots that were occupied by the Apple memory, which...

forums.macrumors.com

 

[Excitable Boy]

I've just got a 2020 iMac to compliment the 2010 one which is still going strong. I uprated the Ram to 64GB using Crucial and have had no issues at all.

When I tried to be cheeky and put the standard 8GB in slots 1 and 3 as well as the Crucial 32GB's in 2 and 4 it reduced the speed of the Ram to 2100 ish .... Having looked on the net I saw that using the original in slots 1 & 2 with the new Ram in 3 & 4 should be ok ... and it was, showed all running at the correct 2666 speed. The thing is I did a Geekbench test on the now 72Gb and found it ran slower than the 64Gb on it's own. I am guessing this is due to the position in the slots as the newer Ram is not in slots one apart, and instead next to each other which obviously it doesn't like as much !

The Geekbench score with 72Gb allegedly running at the correct 2666 was 5800 multi core. If I took out the original 2x4 Gb chips and moved the new memory back to slots 2 and 4 it gave me 6800 multi core ... so guess I am staying at 64Gb and no more. That will teach me to be greedy for another 8gb Ram !

I thought I'd try the Geekbench Appraisal with my new device and it's meagre 32GB RAM allocation, my results were
Viz... Single Core 1285, Multi Core 8466, clearly different to your findings but I don't know if it's good or bad for my machine which is an i7 3.8Ghz with the 5500XT graphics 512GB SSD. I'm not sure why the Geekbench report says my RAM frequency is 1333Mhz under the section 'Memory Information' It's likely my own ignorance so I'm not concerned too much about that.

Also have a 2015 5K iMac that the nearest'n'dearest uses and it's still going strong too, it's not too shabby performance wise either . I'm rather disappointed with this later machine and thinking seriously about moving it on after only a week or so. It's more likely the pernicious OS that I'm unhappy with rather than the machine. So I'll be asking Sherman to set The Wayback for 2012 and the co-ordinates for Ludditesville!

 

[SO8]

I thought I'd try the Geekbench Appraisal with my new device and it's meagre 32GB RAM allocation, my results were
Viz... Single Core 1285, Multi Core 8466, clearly different to your findings but I don't know if it's good or bad for my machine which is an i7 3.8Ghz with the 5500XT graphics 512GB SSD. I'm not sure why the Geekbench report says my RAM frequency is 1333Mhz under the section 'Memory Information' It's likely my own ignorance so I'm not concerned too much about that.

Also have a 2015 5K iMac that the nearest'n'dearest uses and it's still going strong too, it's not too shabby performance wise either . I'm rather disappointed with this later machine and thinking seriously about moving it on after only a week or so. It's more likely the pernicious OS that I'm unhappy with rather than the machine. So I'll be asking Sherman to set The Wayback for 2012 and the co-ordinates for Ludditesville!

Mine is a 3.3ghz i5. Your results are decent I think for that CPU.

 

[Megabass]

Viz... Single Core 1285, Multi Core 8466, clearly different to your findings but I don't know if it's good or bad for my machine which is an i7 3.8Ghz with the 5500XT graphics 512GB SSD

Results of my exact same configuration 1292 - 9046, in Novabench - 30386
I have a memory HyperX HX426S15IB2K2/32