Memory upgrade compatibility list for iMac 2019-2020

[PBG4 Dude]

Please read carefully what i ordered!

LOL whoops

 

[AZREOSpecialist]

You don't need to buy RAM from Crucial. I bought a pair of NEMIX modules from NewEgg and they are running in a matched pair in slots 2 and 4 at 2667 MHz. No problems. The RAM used by 2020 iMac has the same specs as 2019 iMac.

 

[randika100100]

Hi all,
I am new to the forum and also for Apple eco system. Just bought my first iMac 27 inch 2020. What are the dangers of using these third party RAMs? Is there actually a difference in performance. How about long term use? I am looking at Amazon for most of the brands mentioned in this list and at least see one or two saying they 'Bricked' their new iMacs with this third party RAMS.

Please shed some light. What is the difference between Apple original RAM and these third party RAM cards? I mean....... why does apple charge about 3 times the price for the same piece of equipment? Is there a difference in quality?

Is there anyone here who had done this before and used a third party RAM with no issues for more than 2 years?

Is it worth paying Apple and get the original RAM cards?

Sorry for all the questions. I am a total NOOB.

 

[randika100100]

They will be compatible, but not certified for Mac. If you need support in the future, they won't back you. https://www.amazon.ca/Crucial-16GBx.../B07TKZKPJV/ref=sr_1_1?tag=macr05-20&dchild=1 is the good one, fully certified. But those you linked will work as other tested it. Choice is up to you.

EDIT : The certified Mac SKU is virtually not available anywhere in Canada. This is crazy how popular this kit became in the last weeks. In this case I'd date the generic model.

Hi I am a total Noob. Who certifies these? Apple?

Also why apple original RAM cards are 3 times expensive than these third party cards? Is there a performance difference between original Apple RAM cards and these third party cards? I also saw some people had 'bricked' their new iMacs with third party RAM cards but maybe they didn't know what they were doing?

I am so glad I found this forum and individuals like you who has an inside out knowledge about this subject. Thank you in advance!

 

[pldelisle]

Hi I am a total Noob. Who certifies these? Apple?

The RAM manufacturer itself. It ensures its module passes their certification test for every specific machine/motherboard they have listed.

Also why apple original RAM cards are 3 times expensive than these third party cards? Is there a performance difference between original Apple RAM cards and these third party cards? I also saw some people had 'bricked' their new iMacs with third party RAM cards but maybe they didn't know what they were doing?

There is absolutely nothing to justify these prices. Apple put Hynix RAM and Micron (crucial) RAM as stock RAM in their iMac. Nothing fancy. No performance gain over third party RAM. Nobody can brick an iMac with RAM listed in first post, it’s impossible.

 

[longtom]

OK, ordered now 128gb: 2x Crucial CT2K32G4SFD8266 64GB Kit (32GB x2) Speicher (DDR4, 2666 MT/s, SODIMM, 260-Pin, 1.2V, CL19).

Working fine now with 128GB in my iMAC 2020.
I updated the list in the first post, OK @pldelisle ?

 

[ninecows]

Why doesn’t anybody mention Corsair ram? Is it just low life crap that you should stay clear of? It’s like 25% less in price than Crucial where I am. Would this work?

CMSA64GX4M2A2666C18

 

[longtom]

Yes, they'll work as they are "MAC" RAM.
Still more expensive (in Europe) than CT2K32G4SFD8266

 

[ninecows]

Yes, they'll work as they are "MAC" RAM.
Still more expensive (in Europe) than CT2K32G4SFD8266

Thanks. It is Mac ram (at least it’s labeled as such).

The crucial you linked to seems sold out in Denmark and the price difference was only around 5% so I went for the Corsair.

I will report back how they behave. Still a bit surprised not to see that brand mentioned at all on 11 pages of “compatible ram”.

 

[pldelisle]

Thanks. It is Mac ram (at least it’s labeled as such).

The crucial you linked to seems sold out in Denmark and the price difference was only around 5% so I went for the Corsair.

I will report back how they behave. Still a bit surprised not to see that brand mentioned at all on 11 pages of “compatible ram”.

Good point. Hard to say which manufacturer Corsair memory comes from, but Corsair is usually good memory.

 

[ThuNd3rZ]

hi, I was just wondering what is the difference between these 2 ram kits, other then then the label ( mac)? Will the second one work the same and save me some money?

Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM for Mac | CT2K32G4S266M | Crucial.com

Buy Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM for Mac CT2K32G4S266M. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM | CT2K32G4SFD8266 | Crucial.com

Buy Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM CT2K32G4SFD8266. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

 

[pldelisle]

hi, I was just wondering what is the difference between these 2 ram kits, other then then the label ( mac)? Will the second one work the same and save me some money?

Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM for Mac | CT2K32G4S266M | Crucial.com

Buy Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM for Mac CT2K32G4S266M. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM | CT2K32G4SFD8266 | Crucial.com

Buy Crucial 64GB Kit (32GBx2) DDR4-2666 SODIMM CT2K32G4SFD8266. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

Both work. Both have been tested by users in this thread.

 

[longtom]

With the "M" the "tested" MAC version.
You can buy the cheaper one. ;-)

 

[randika100100]

The RAM manufacturer itself. It ensures its module passes their certification test for every specific machine/motherboard they have listed.


There is absolutely nothing to justify these prices. Apple put Hynix RAM and Micron (crucial) RAM as stock RAM in their iMac. Nothing fancy. No performance gain over third party RAM. Nobody can brick an iMac with RAM listed in first post, it’s impossible.

Thanks so much for this! One last question. I have the 2 x4 GB sticks that came with my iMac. Should I remove them and install my 2x 16 GB cards or can I use all four and get up to 40GB?

 

[wilberforce]

Thanks so much for this! One last question. I have the 2 x4 GB sticks that came with my iMac. Should I remove them and install my 2x 16 GB cards or can I use all four and get up to 40GB?

See 7:02 in this video:

 

[pldelisle]

Thanks so much for this! One last question. I have the 2 x4 GB sticks that came with my iMac. Should I remove them and install my 2x 16 GB cards or can I use all four and get up to 40GB?

You must remove them.

 

[longtom]

Why?
In my MAC 2017 i had 40GB of RAM.
2x16GB plus the original 2x4GB, running with correct speed!
Try it with 40GB and checkbthe clock speed in System.

 

[MacManiac76]

Thanks so much for this! One last question. I have the 2 x4 GB sticks that came with my iMac. Should I remove them and install my 2x 16 GB cards or can I use all four and get up to 40GB?

You must remove them.

Not necessarily. The mixing of RAM has only been an issue recently with the 2020 iMac. I have had both Crucial and the original installed RAM in my 2019 iMac for a total of 40 GB of RAM at the full 2667 MHz speed in dual channel mode.

 

[wilberforce]

Why?
In my MAC 2017 i had 40GB of RAM.
2x16GB plus the original 2x4GB, running with correct speed!
Try it with 40GB and checkbthe clock speed in System.

Yes, in all iMacs, except the 2020 27" iMac, this is fine.
For 2020 27" iMac see video in post #265, at 7:02.
Apple's memory upgrade instructions for the 2020 27" iMac, and only for the 2020 27" iMac, state:
"For optimal memory performance, DIMMs should be the same capacity, speed, and vendor."
As to why - who knows? I assume Apple knows, but they are not saying. It may even be a bug.
It is what it is (although I hate that expression!).

 

[pldelisle]

Not necessarily. The mixing of RAM has only been an issue recently with the 2020 iMac. I have had both Crucial and the original installed RAM in my 2019 iMac for a total of 40 GB of RAM at the full 2667 MHz speed in dual channel mode.

2019 != 2020.

2020 is really picky. The same setup as yours won't run at full speed on 2020 iMac.

 

[longtom]

So, try and error. ;-)

 

[MacManiac76]

2019 != 2020.

2020 is really picky. The same setup as yours won't run at full speed on 2020 iMac.

I know that. That is why I stated in my reply that the mixing and matching issue only applies to the 2020 iMac. This thread is not only about the 2020 iMac so you should not just blindly say that mixing and matching RAM will not work for everybody here.

 

[pldelisle]

I know that. That is why I stated in my reply that the mixing and matching issue only applies to the 2020 iMac. This thread is not only about the 2020 iMac so you should not just blindly say that mixing and matching RAM will not work for everybody here.

I assumed the user had a 2020...

I am new to the forum and also for Apple eco system. Just bought my first iMac 27 inch 2020.

... which in fact he had.

So what's the problem again ?

 

[The French Man]

HI,

2 X 2X32 GO in my new iMac 27' 2020
That works fine
HyperX Impact DDR4 HX426S16IBK2/64 Mémoire RAM 2666MHz CL16 SOIMM 64Go Kit (2x32Go)

HyperX Impact HX426S16IBK2/64 Mémoire 64Go Kit*(2x32Go)2666MHz DDR4 CL16 SOIMM

HyperX Impact HX426S16IBK2/64 Mémoire 64Go Kit*(2x32Go)2666MHz DDR4 CL16 SOIMM

www.amazon.fr

 

[MacManiac76]

I assumed the user had a 2020...



... which in fact he had.

So what's the problem again ?

There is already another thread for the 2020 iMac RAM compatibility issues. This thread should be renamed to 2019 iMac and earlier or something so that no assumptions have to be made in this thread anymore.