Anybody seen Samsung/Micron/Hynix 32 GB DDR4-3200 ECC UDIMMs in the wild?


I’m a bit fed up with waiting for Samsung ECC UDIMMs with 32 GB each that are faster than DDR4-2666.

Samsung’s website lists 3 sticks with 32 GB:

M391A4G43MB1-CTD - DDR4-2666

M391A4G43AB1-CVF - DDR4-2933

M391A4G43AB1-CWE - DDR4-3200

All three are to merely be at the “Sample” state which is clearly incorrect since even as an end customer you have been able to buy the DDR4-2666 model for about eight months now.

Does anybody have some “insight” here?

Thanks for the assist!

aBavarian Normie-Pleb

As of 2020-04-11, I get the same answer as you got, for all three variants: Sampling.


I had an order placed in January for qty 4 of M391A4G43MB1-CTD. It was delayed twice, with a final ship date of this week. Unfortunately, today I heard it was back ordered until August 2020. They said they had a 2 week (not 3 month) lead time when I placed the order, which I was fine with. I didn’t even try to buy the fast ones @ 3200… Rep said that the company had 4 other people with orders of the exact same product in the queue as well.

I suspect Samsung’s batch of these has well and truly dried up, and they simply have not made any new batches of them.

I am really surprised that the market for DDR4 ECC UDIMMs seems to have demand driven by all of the new ryzen 3 chips, and more critically the threadripper chips, but there does not seem to be a response by any manufacturer - except for Samsung’s sample run. I’m personally trying to pair ECC capable memory with a threadripper myself. I’ve read multiple reports of it working rather successfully on 3000 series TR’s.

A bit strange that you can’t get them, for example in Germany the M391A4G43MB1-CTD are quite available to retail customers on various regular online shops.

Hi aBav.Normie-Pleb, have the 3200 models shown up in Germany recently - or are they still difficult to locate?

No, unfortunately from Samsung only the M391A4G43MB1-CTD 32 GB DDR4-2666 ECC UDIMMs have shown up (original thread posting/question still valid).

Ordered six of them in March 2020 for systems I got to build, these units of the M391A4G43MB1-CTD were manufacured in week 5/2020. The earliest modules I used last year are dated week 11/2019. All of these run with DDR4-3200/1.20 V and loose auto-timings on AM4 systems without issues (yet). Above DDR4-3200 it starts to get tricky, but presently I don’t have the patience to further experiment beyond that.

For a short time, Crucial’s 32 GB DDR4-3200 ECC UDIMMs showed up in end-customer price listings, but they were never actually available before they disappeared again.


Can you tell me where you bought your kits? Do they all perform similarly in terms of overclocking (did you get around to adjusting timings)?

You say you have six sets, where were they made? (samsung RAM usually made in Korea, Philippines or China). Btw I reached out to a few suppliers and like you, couldn’t find faster than 2666 but I wanted to get some info before I make a purchase.

@bitcore do you mind telling me what shop you had that experience with so I can avoid it? (pm if you don’t want to post their name publicly).

Cheers has them in stock pretty sure. OC people have gotten them to 3200 pretty sure on this forum.

Thanks for the tips, do you by any chance have them? I read that they mostly overclock to 3200 with everything else set to auto, but anyone tried further adjustments (timings)?

Would you consider these the best choice for an ECC Ryzen build, or other modules like those from crucial?

Does memory speed even really matter in your application? People get super tunnel vison on it. it’s most likely not going to be detrimental unless your running it at 100% 24/7


I haven’t seen Samsung DIMMs, but I do have 32GB Crucial DDR4-3200 ECC DIMMs running on my ASRock X470 Taichi system. The part number is MTA18ASF4G72AZ-3G2B1. I bought them from

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Nice, these seem to be the ones that had appeared in European hardware retailer listings for a short whilebut then vanished again :frowning:

Do you have a Zen 2-Ryzen on your X470 Taichi? Would be nice to know if you could get the Crucial DDR4-3200 ECC UDIMMs to DDR4-3600/3800 with 1800/1900 MHz FCLK at 1.35 V.

Completely unrelated questioon: Does anybody know if Crucial has a worldwide warranty RMA coverage, so there wouldn’t be much risk with personally importing a few pieces from the US to Europe since for some reason Crucial deems us unworthy…

The CPU is a Ryzen 5 3600. I haven’t tried overclocking the RAM. I might if I find the time but this is my main system now and I’m not sure I can afford the downtime to thoroughly test 128GB of RAM.

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General information: Got another two Samsung M391A4G43MB1-CTD 32 GB DDR4-2666 EUDIMMs this week and these modules had been manufactured 2020 week 9.

I picked up the 32GB (DDR4-3200) version of these (MTA18ASF4G72AZ-3G2B1) at CDW: There site availability says 4-6 weeks but I received mine in a week. They sent them out in just a mailer, so you might want to call and request they get shipped in a box.

I’ve been testing them on my Gigabyte trx40 Aorus Xtreme w/ 3970x with Memtest86 and everything looks good. I am using 8 Dimms for a total 0f 256GB. Since Gigabyte only corrects one bit errors but doesn’t report them, I have no way of knowing if there are a ton of errors in this config that are getting corrected, or if it is stable at the current settings (i.e. these are not running at an overclock so the voltage is only 1.2V, typically one would see 1.35V on XMP settings. Running 8Dimms of 3200MHz at only 1.2V seems like it would be a challenge for trx40 boards based on the information floating around in the forum, although the stock timings are fairly loose). Memtest86 reports that the memory has ECC but that it is not enabled. From what I’ve read elsewhere, Gigabyte enables ECC correction out of the box but since it doesn’t enable reporting the errors, Memtest86 thinks it’s not enabled.

Finally got my hands on two Micron 32 GB DDR4-3200 ECC UDIMMs (MTA18ASF4G72AZ-3G2B1).

Initial impression: The modules (obviously) clock higher than Samsung’s 32 GB DDR4-2666.

Can run the two Micron DIMMs @DDR4-3800 (1.30 V), unfortunately the IF clock of the 3700X available for toying around seems to only work up to 1800, not 1900 MHz without further tuning I have no time for.


That is great news!

Do you run it on a Asus WS x570 Pro ACE with the R73700X?


My combo (3900 Pro + 4 x 32 GB Samsung DDR4-2666 ECC UDIMM + ASUS Pro WS X570-ACE) is going to be my home server, so no more experimenting there.

My Zen 2 experiments are currently done on an ASRock X570 Taichi (UEFI P3.20) Rev. 1.05 and said 3700X.

well, I have ordered two modules and will try it on my WS pro - I’ll let you know my results.

Thanks to you all for starting this thread and making me aware that they are available: this solves many headaches.