Do you have something against Mexico? 😂
[automerge]1602850559[/automerge]
Can’t say for sure on this picture. But my guess is that it will fall back to JEDEC standard on CL19.
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Memory upgrade compatibility list for iMac 2019-2020
- Thread starter pldelisle
- WikiPost WikiPost
- Start date
-
- Tags
- imac
- Sort by reaction score
- Status
[automerge]1602850559[/automerge]
There were many threads starting at the launch of the iMac 2020 regarding wether or not memory modules were compatible or not. This thread was a summary of all certified modules and for people letting know to others that what they bought was working or not. iMac 2020 was fancy on which RAM work or not.
Ok, but again nobody has claimed that some particular memory wasn't working. Just a lot of people asking the same question and discussing ram in general. I appreciate all the effort you went to but you would have been better off asking people to post ram that doesn't work. Of course, it would be pretty quite in here if you did that.
The imac needs DDR4 2666mhz SODIMM. That's the only requirement. Timings, voltages, etc. will all be within tolerance ranges. Doesn't matter the brand or capacity, as long as it's not defective (always test modules after installation).
Personally, I'm going with Nemix because they're almost half the price of the next cheapest brand.
I've had issues with mac-specific ram made by 3rd parties in the past. Things might work great at first but then get wonky down a few months later. It'll even pass all diagnostics, but as soon as you slap in official apple ram, all problems go away
Last edited:
I think you are a bit complaining for nothing. The goal was just to make clear what is certified compatible, what you should buy. Yes, people can post in here modules that doesn’t work, but the goal was exactly to avoid buying things that don’t work.
I personally find a computer of that price, especially an iMac, shouldn’t have such cheapo RAM. But that’s your money, not mine.
Doesn't matter but memtest86 is good. Usage video: How to create Memtest86 USB for Mac | How to Test iMac Memory
That's good to know.. You can also use Apple HW Diag by holding down D when booting up
I installed Crucial CT2K32G4SFD8266 64GB Kit (32GB x2) on my 27" iMac 2020 at Slot 1,3 (Just replaced with the original rams)
The system said they runs at 2667Hz, but the Geekbench 5 report said it runs at 1333Hz....
It gave around 8500 Multi-core score (Mine is i7 8 core )
Is this normal? Are they running at dual channel?
The system said they runs at 2667Hz, but the Geekbench 5 report said it runs at 1333Hz....
It gave around 8500 Multi-core score (Mine is i7 8 core )
Is this normal? Are they running at dual channel?
Here is my geekbench report
iMac20,2 - Geekbench
Benchmark results for an iMac20,2 with an Intel Core i7-10700K processor.
browser.geekbench.com
Hi AppleFans
iMac (Retina 5K, 27-inch, 2020)
3,8 GHz 8-Core Intel Core i7
AMD Radeon Pro 5500XT 8GB
Mac OS Catalina 10.15.6
I have tested 3 different sticks and this is the result :
CRUCIAL Total 32GB -- 2x 16GB Crucial CT16G4SFD8266 - DDR4 2666 1.2V CL19 - Geekbench 8890
CORSAIR Total 64GB -- 4x 16GB Corsair CMSX32GX4M2A2666C18 - DDR4 2666 1.2V CL18 - Geekbench 9030
SAMSUNG Total 32GB -- 1x 32GB Samsung M471A4G43MB1-CTD - DDR4 2666 1.2V CL19 - Geekbench 7730
SAMSUNG Total 64GB -- 2x 32GB Samsung M471A4G43MB1-CTD - DDR4 2666 1.2V CL19 - Geekbench 8810
I have tested 32GB Crucial and 64GB Corsair and CRUCIAL is the winner ! and its between 32 and 64GB.
I hope this helps
iMac (Retina 5K, 27-inch, 2020)
3,8 GHz 8-Core Intel Core i7
AMD Radeon Pro 5700XT 16GB
Mac OS Catalina 10.15.7
CRUCIAL Total 64GB -- 2x 32GB Crucial CT32G4SFD8266 - DDR4 2666 1.2V CL19 - Geekbench 8450
WHY...
Last edited:
I don’t see any problem. Geekbench probably report the data rate, which is 1333 mhz. The double data rate (DDR) speed is 2666 mhz.
Hi!
+1 searching differences between CRUCIAL CT2K32G4S266M and CT2K32G4SFD8266.
It looks like there are not so much differences...
Concretely, what are the risks of using the non-mac memories?
Is it possible to see some potential problems after months of use?
Are the geekbench tests totally the same?
Thanks for your precious help!
+1 searching differences between CRUCIAL CT2K32G4S266M and CT2K32G4SFD8266.
It looks like there are not so much differences...
Concretely, what are the risks of using the non-mac memories?
Is it possible to see some potential problems after months of use?
Are the geekbench tests totally the same?
Thanks for your precious help!
The only difference is in the materials used for building the PCB. One is lead free, which complies with Apple environmental policies. The other is not. The DRAM used is exactly the same. Both work fine in 2020 iMac.
In this case, none.
Not with this one.
Yes
so are there any updates for the people that got the 32gb sticks of samsung ram and were getting shutdowns when trying to use 4 of them?
trying to get 64gb(2x32) right now and add more in the future so can't decide between the samsung or crucial.
trying to get 64gb(2x32) right now and add more in the future so can't decide between the samsung or crucial.
I'm leaning towards but the savings on the samsung would be nice. The reviews seem to be good for it too other than that one person with the 4 sticks problem.
Your iMac bench market looked even better than the official one:
.
So nothing to worry about.
I want to add that CL19 (CAS latency) is not a requirement for imac memory. Most manufacturers use CL19 timings in their DDR4 2666mhz modules, except one: Kingston HyperX at CL15 for 16GB modules (CL16 for 32GB).
The performance difference depends on the application but you can expect at least +5% in games and even more in other usages like rendering or simulations. The Kingston ram is the same price as the other brands plus they test the fully assembled modules. Other manufacturers generally only test the raw chips before they go down the assembly line.
According to Amazon reviews, many people are successfully using them in their 2020 imacs. I plan to use them myself in a few weeks.
https://www.amazon.ca/dp/B08492TQGQ/
https://www.amazon.com/dp/B01N7K4DV4/
The performance difference depends on the application but you can expect at least +5% in games and even more in other usages like rendering or simulations. The Kingston ram is the same price as the other brands plus they test the fully assembled modules. Other manufacturers generally only test the raw chips before they go down the assembly line.
According to Amazon reviews, many people are successfully using them in their 2020 imacs. I plan to use them myself in a few weeks.
https://www.amazon.ca/dp/B08492TQGQ/
https://www.amazon.com/dp/B01N7K4DV4/
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
I've read that the Kingston HyperX will run at CL19 in an iMac 2020 - have you seen otherwise?
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
I have not seen otherwise but that would be very bizarre if true. A memory controller will not modify the timings unless it's trying to keep them within voltage limits or bring all the modules down to the lowest common speed. Since the HyperX modules are designed to operate at CL15 at 1.2V at a 2666mhz frequency (per JEDEC spec), that's what you will get.
It sounds like someone mixed the HyperX modules with the stock modules, and it downclocked to the stock ram at CL19.
Anyways, I'm happy to test it and report back when the imac arrives.