From *every* memory vendor selling DDR4 RAM (1.2v is standard DDR4 voltage) and 2666 Mhz RAM (CL19 is JEDEC standard for 2666Mhz memory).
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Memory upgrade compatibility list for iMac 2019-2020
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Is there a way to confirm this on the stock apple RAM? does it have it printed on the ram itself or is there a RAM model number we could google to confirm Apple RAM is the same V and CL?
Good luck to find a DDR4 standard module with another voltage than 1.2v.
CAS Latency can usually be found on the sticker on the memory module. But if *all* memory vendors sell CL19 as iMac RAM, it has CL19 for sure.
The module listed is missing the "-CTD" at the end of the part number, would this make any difference? Also, they only sell the singles, and you mentioned it's better to buy the kits, would you still recommend 2 of these over the TimeTec which does sell the kit?
Thanks.
I don’t think the -CTD means really something. I really can’t find any of these modules with -CTD.
I would buy 2 Single modules over TimeTec memory since I know the source of DRAM chips. I can’t find the DRAM supplier of TimeTec.
Thanks, went with the Samsung's, like you said it's the better brand. The TimeTecs were temping because of the black boards and they're made in the USA, I like to support US companies when I can. They were both around the $240, so quite a bit cheaper than Crucial or OWC.
@maflynn Can we pin this thread ? There are many questions about RAM with the release of the new iMac. Thanks !
While I have faith in Micron to manufacture quality memory modules, I have less faith in their Crucial division to coherently market them.
The 8266 vs S266M question has come up before, and often, and user experience has borne out that the former will function fine in the '19 iMacs. I've had them installed in my machine for two months short of a year, in coexistence with the OE Hynix modules, without any issues.
The Crucial website is a mess, with compatibility guides spread over various online and PDF documents, and an advisor that sometimes acknowledges the existence of some Apple models, but not others.
Enter the advisor from the main site, and it properly knows the '18 and '20 minis are real products, and list the cited modules as compatible.
Go to the modules' product pages, and ask the "Will it work?" guide and the late model minis aren't even listed as a choice.
It seems that there are at least two different advisors at work, and if not, then at least two different databases being drawn from, with no unified, consistent, and thus trustworthy source to rely on. The same mixed messaging was propagated by Crucial reps answering Amazon Q&As when the '19 iMac first appeared, with some saying particular modules were compatible, and then not.
Going back to the "M-or-not" question, the one thing that can be reasonably divined from Crucial's website is that they both share the same electrical characteristics, with the only apparent difference being that the Mac-targeted modules are made with greener materials. When contacted directly, a Crucial rep could only offer the same conclusion.
But, one may ask, what does the mini have to do with this?
Well, if their website is to be trusted, if the 8266 memory is recommended for the '18 and '20 minis, then why not the iMacs, since Apple installs the same memory (HMA851S6CJR6N-VK) for both models at the factory, as confirmed by teardowns and System Profiler reports?
Apple does not spec different modules for the '18/'20 minis and '19/'20 iMacs, so why does Crucial?
That is the question that should be answered, by a reliable source.
I just purchased four of these, will let you know later this week how they perform on the 2020 i7:
Patriot Signature Series 8GB 2666MHz (PC4-21300) DDR4 SODIMM Memory Module
Patriot Memory's Signature Line DDR4 SODIMM memory delivers the quality, reliability and performance expected for today's notebook needs. This 8GB module is designed to run at 2666MHz (PC4-21300) at CAS 19 latency timings. Built using specific build-of-materials (BOMs) we ensure that every module...www.amazon.com
FYI confirmed these work, all showing as 8 GB at 2667 MHz.
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Any thoughts on PNY ?
PNY Performance 32GB DDR4 DRAM 2666MHz (PC4-21300) CL19 (Compatible with 2400MHz or 2133MHz) 1.2V Notebook/Laptop (SODIMM) Computer Memory RAM – MN32GSD42666
Want to work with the latest memory-intensive applications like graphic design and video-editing tools? Like to keep lots of browser Windows open for work, school, or play? Is your PC having trouble keeping up? A DDR4 2666MHz Memory upgrade from PNY gives you the speed you need to get the most ou...
www.amazon.com
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Are you planning to use only these Samsungs sticks or keep the original Apple RAM as well?They're here! Now I just have to wait for my iMac...
I can’t find any system specific parts for the iMac. I think PNY only makes generic RAM. We can’t certify it will be compatible in Macs.Any thoughts on PNY ?
PNY Performance 32GB DDR4 DRAM 2666MHz (PC4-21300) CL19 (Compatible with 2400MHz or 2133MHz) 1.2V Notebook/Laptop (SODIMM) Computer Memory RAM – MN32GSD42666
Want to work with the latest memory-intensive applications like graphic design and video-editing tools? Like to keep lots of browser Windows open for work, school, or play? Is your PC having trouble keeping up? A DDR4 2666MHz Memory upgrade from PNY gives you the speed you need to get the most ou...www.amazon.com
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Just to be clear: If I buy 2 of these 2x HyperX RAM blocks, they should be OK to use in an iMac 2020?
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I al have a set of those Samsung 32GB; tried all combinations and faced same problems mentioned in other brands.
I think the issue is not the brand but mixing sizes.
Totally useless to buy this RAM. Please refer to first post for 100% compatible part list.
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I don’t think.
Most motherboards even in the after market doesn’t like mixing brands and DRAM chips.
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Was originally planning on using both, but after all the reports I think I'm just going to stick with the 64gb of Samsung RAM. I could try out both just to see how it works, but someone in this thread already claims it doesn't.
What are peoples thoughts on Samsung RAM? Looking at getting 2 of these for $250 for 64gb total while leaving the other 2 slots open for future upgrade to 128gb, or would it be ok to leave the 8gb from apple in there and have 72gb?
Samsung 32GB DDR4 2666MHz RAM Memory Module for Laptop Computers (260 Pin SODIMM, 1.2V) M471A4G43MB1
Samsung 32GB DDR4 2666MHZ PC4-21300 SODIMM M471A4G43MB1-CTDwww.amazon.com
I got these delivered yesterday and they work perfectly on my iMac. I removed the 8gigs, but these do show on the list above so I am thinking they can be added back if needed.
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What do you think about using:
1. HYNIX model HMA81GS6CJR8N-VK;
1. Timetec model B07L199BMS?
Should it work flawlessly with memory already present in the iMac?
1. HYNIX model HMA81GS6CJR8N-VK;
1. Timetec model B07L199BMS?
Should it work flawlessly with memory already present in the iMac?
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Theoretically the Hynix yes, but I still don't know the model of Hynix memory shipped with 2020 iMac. So it might be a guess. The iMac seems really picky about having different DRAM chips in it.
I don't really "trust" Timetec. I don't know what to think about this company. In my book, Crucial is first for using top notch Micron DRAM chips, Kingston second for its legendary reliability and compatibility, and Samsung because it's a good DRAM manufacturer and OEM. Hynix for consumer is almost non-existant, very difficult to verify compatibility prior buying (no memory configurator on their website for instance) and hard to find.
EDIT : I found a memory configurator https://memory.net/store/?filter_fo...3&filter_voltage=1-2v&filter_made-by=sk-hynix
I would stay in these part numbers I think.
Someone who have a 2020 iMac can write down in this thread the part numbers of the RAM shipped with their iMac ?
I don't really "trust" Timetec. I don't know what to think about this company. In my book, Crucial is first for using top notch Micron DRAM chips, Kingston second for its legendary reliability and compatibility, and Samsung because it's a good DRAM manufacturer and OEM. Hynix for consumer is almost non-existant, very difficult to verify compatibility prior buying (no memory configurator on their website for instance) and hard to find.
EDIT : I found a memory configurator https://memory.net/store/?filter_fo...3&filter_voltage=1-2v&filter_made-by=sk-hynix
I would stay in these part numbers I think.
Someone who have a 2020 iMac can write down in this thread the part numbers of the RAM shipped with their iMac ?
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My 2020 i7 iMac came with 2x4GB Hynix HMA851S6DJR6N.
I am not sure what you consider compatible as per the original post but it seems like for instance the Crucial 2x16GB CT2K16G4S266M cannot be run at the correct speed when inserted together with the original RAM for a total of 40GB. More information can be found in the following thread: Memory upgrade troubleshooting in 2020 27-inch iMacs. I have yet to find time to run more tests myself but the findings in that thread seem to indicate that they will run at the correct speed when running without the original RAM.
Possible.
iMac seems not to like mixing Hynix and Micron DRAM chips (like many other consumer grade motherboard).
Compatibility is guaranteed when not mixing parts. Micron obviously cannot guarantee their RAM module to work with the planet. They guarantee they work with only their modules installed. You won't be able to run Micron and Hynix DRAM chip together in an iMac in Dual channel configuration.
So I would try to find these exact HMA851S6DJR6N-VK modules if one would like to run entirely on Hynix RAM with 16 GB of RAM total. For higher capacity, sell your HMA851S6DJR6N-VK modules and get 4 Crucial/Kingston/Samsung/Hynix modules.
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According to this webiste above-mentioned memory chip is 3200Mhz. So maybe 3200Mhz memory chips would work correctly with these and maybe this is why 2666Mhz ones are causing problems?
EDIT:
Unfortunately I was unable to find 3200Mhz 8GB DDR4 CL19 SO-DIMM RAM for sale
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