DDR4 RAM Buy or OC for 3200 ECC unbuffered?

Looking around for 3200GHz spec ECC unbuffered RAM for a new build and there doesn’t seem to be many options available.

I’ve located MTA18ASF4G72AZ-3G2B1 but that’s 32GB per stick which tbh means 64GB to benefit from dual channel see https://www.elara.ie/productdetail.aspx?productcode=ECE5668920 from a local retailer.

I’ve also come across ME25600-628K02-G from NEMIX https://www.newegg.com/p/1X5-003Z-01918?Description=unbuffered%20ECC&cm_re=unbuffered_ECC--9SIA7S6BUD5388--Product

Not familiar with NEMIX and reading https://forums.anandtech.com/threads/beware-of-nemix-ram.2583432/ isn’t helping my confidence about importing into Ireland (EU) and potentially having to ship back if there are any issues.

I’ve located the part number for a 16GB version of the Micro RAM available locally - https://pcpartpicker.com/product/ML7p99/micron-16-gb-1-x-16-gb-ddr4-3200-memory-mta18adf2g72az-3g2e1

And of course as soon as I put together this post, I managed to enter the right part number into a local distributor - https://www.elara.ie/productdetail.aspx?manufacturer=CRUCIAL&mancode=MTA18ADF2G72AZ-3G2E1

Course that’s not available for about 2 weeks, so if anyone is aware of other part numbers from manufacturers that match my preferred specs I would be very grateful if you could share them.

The alternative I’m considering is whether it’s just better to try and purchase some memory that is known to overclock to the desired speed? I’m planning on a Ryzen 5 3600 (or better) coupled with an X570 board. I’m guessing if I need to go this route instead, will definitely want a better cooler for the CPU assuming it has some impact with multipliers. Though I’m guessing it might disable CPU boost speeds doing this unless the OC memory lines up with a particular clock speed?

Adding the product numbers found here to help anyone searching:

  • M391A2K43DB1-CWE - Samsung
  • MTA18ADF2G72AZ-3G2E1 - Micron
  • KSM32ED8/16ME - Kingston

I don’t think you’ll be able to find any ECC known to overclock well. You might be able to get 2,666 MHz up to 3,000 MHz or close to it, but more than that is doubtful.

So if you really want that 3,200 MHz then get the RAM spec’d for it.

It’s my opinion but I think the main problem is the RAM chips are picked over by the manufacturers and the high speed chips are binned for gaming RAM. The leftovers are used for everything else including ECC/server RAM.

I have used 16 x Samsung 32 GB DDR4-2666 UDIMMs in various X470 and X570 builds over the past year and every one of these builds works with DDR2666@3200 at 1.20 V and default Auto-Timings.

I’ve also been looking for faster ECC UDIMMs for quite a while.

When checking listings it seems Micron’s 32 GB DDR4-3200 ECC UDIMMs (MTA18ASF4G72AZ-3G2B1) will be the first to be generally available in Europe (will get a pair as soon as they are really shipping).

I had also tested Crucial 16 GB DDR4-2666 ECC UDIMMs, they wouldn’t even run at DDR4-2933 with 1.35 V.

Personal opnion based on the six years of DDR4 purchases: Samsung’s the best for DRAM (and SSDs).

Dont bother, it works but might not hit rated spec.

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Thanks, it’s my preference to avoid needing to OC to get decent speeds from the memory, though I have been reading some people are having success with particular batches

Subscribed to the referenced topic. Looking up the Samsung 32GB model has led me to the 16GB model M391A2K43DB1-CWE so I’ll start searching for that as well.

Any particular reason to want/need the high speed RAM? The CPU itself will work just fine with even generic cheapo 2133mhz RAM, as it will run and boost at the correct speeds. If that is your worry then that depends more on whether your motherboard’s VRM and your CPU cooling is up to task, not the speed of the RAM used.

As I’m using ECC I don’t expect there where be any special XMP combinations so I won’t benefit in trying to match memory to motherboard which can have an impact as described at https://www.gamersnexus.net/guides/3508-ryzen-3000-memory-benchmark-best-ram-fclk-uclock-mclock.

Instead it’ll probably be limited to raw latency improvements based on https://eu.crucial.com/articles/about-memory/difference-between-speed-and-latency where the 2666MHz memory I was looking at is CL19 and the 3200MHz is CL22 based on https://www.memorysolution.com/16gb-samsung-ddr4-3200-cl22-1gx8-ecc-dr.html which lines up with a best case scenario of up to 3.5% improvement for memory bound operations. Which I’ll grant you is not exactly going to line up with average usage.

I do a lot of local compiling using ramdisk storage rather than disk storage on my PC, so the relatively small benefit will have a more noticeable impact for local builds for me than I’d expect for general gaming. I expect to be using up to ~10GB of memory for certain builds. Additionally the rest of the time as I’m using Linux, which is fairly aggressive in memory use for caching files, it does tend to give a decent benefit for things that involve lots of reads on the same set of files provided there is enough memory to just keep reading files into RAM.

So I’d concur, this isn’t necessarily something that everyone should follow, it’ll depend on usage. I’m not sure if Windows does the same level of caching files in memory that Linux does, it may well do so but hide it in the memory usage figures since as applications need more memory the OS can just discard pages that were in use for a file cache to allow more memory to be consumed. So not always necessary to show that it’s being used by the OS to speed file reads up.

Turns out I missed an existing topic on this 16GB ECC UDIMMs in a time of Ryzen 3000

First, apologies if this post resurrects a zombie thread, but it’s one of the few, semi current threads on Ryzen ECC, UBuffered RAM, and overclocking that’s easily findable.

My experiences in this include overclocking 8 GB sticks of Samsung M391A1K43BB1-CRC, of the famed “B Die” line, which, sadly, is no longer available. It was rated for 2400 MHz (technically 1200, given DDR, but let’s stick with the big numbers for now), and happily overclocked to 3200 (18-22-22-52 1T).

While quite the overclock, with newer AMD processors capable of supporting faster speeds, I’ve been looking for something to use in future builds, which is how I found this thread.

Picked up two sticks of this, for probably too much money, but they are nice:

  • Ram is dual rank, each side of the stick is populated with chips
  • sticks are ultra low profile (low height), so fit underneath my Noctua NH-D15 fan with ease
  • they do overclock, and pass Memtestx86 with ECC error inject on (or off)
  • data sheet claims max operating temp of 95 C (very nice, given lack of heatspreaders)

Ryzen 5 2600 at stock speed (with PBO enabled)
Asrock x470 Gaming K4

With stock timings (rated for 3200), and a little extra voltage (1.3 v [stock is 1.2v]) the ram goes to 3466, with Memtest numbers that look like:

L1 cache 12x96K 88.80 GB/s or 90936 MB/s (real 6x 32K L1, 6x 64K L2 2x 8M L3
L2 cache 12x512K 78.78 GB/s or 80673 MB/s
L3 cache 16M 31.90 GB/s or 32667 MB/s
Main memory 31.9GB 19.24 or 19.707 GB/s
Mem latency 60.667 nSec

This seems to be the sweet spot, latency wise. To get any faster, have to start relaxing the timings, which did get it to 3600, with worse latency and numbers ( for whatever reason, L2 cache numbers go to hell above 3466 - must be a multiplier or Infinity Fabric crossover point).

So, given these speeds were reached on old hardware, the ram may do even better with newer hardware (Zen 3 series).


Hi folks. I wanted to leave some breadcrumbs by linking this honestly very exciting reddit thread that may interest the lot of you (and myself):

This is the Kingston memory with Micron Rev.E 16Gbit IC’s clocking to 3800.

I believe that suffices to prove

I don’t think you’ll be able to find any ECC known to overclock well.


It looks like it may be possible to obtain micron rev E 32GB sticks at around $170 at the present time. But the prices were very nice 2-3 months ago, they have been steadily climbing since then. I can’t really make my mind up on whether to wait or try to purchase now.

Edit just realized I replied to a months old post in a necroed thread :man_facepalming:

Did you adjust SoC voltage or mess with command rate and gear down? Setting the correct procODT was critical for stability as well.

For overclocking the ecc in my old 1950x, simply setting the ram voltage was not enough. For the older boards DRAM Calculator for Ryzen (v1.7.3) Download | TechPowerUp would get you 95% there. Not sure about the newest generation.

I for now gave up on manual memory timing tightening (only have systems with ECC memory) since just about every AGESA update changed the impact on the stability.

Due to a lack of experience there I unfortunately don’t have a good “gut feeling” what’s wrong with memory settings.

But I’d like to revisit this with AM4 nearing its end of life and hopefully all the AM4 AGESA update stuff just focusses on bug fixes and not major changes.

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