NEMIX RAM 32GB DDR4-3200 PC4-25600 2Rx8 ECC Unbuffered Server Memory

These 4 x RAM sticks worked right out of the box. In a QNAP NAS.

This NEMIX memory (the 32 GB ECC sticks) was recognized and works in my ASRock Rack x570d4u-2L2T motherboard, despite the fact that I've tried a couple of other brands of ECC memory that were not recognized.I've also tried the 16 GB sticks of NEMIX ECC memory in this motherboard, and they worked as well.Bottom line: overall, I've been impressed with the NEMIX unbuffered ECC memory, which has always been recognized by my motherboard.

Crashing on an asrock rack x470 board, will return

ECC works and seems stable and memtest86 passes every test EXCEPT the hammer test. I don't know if it's the RAM, or the AGESA, but I'm leaning towards the latter. Whenever in 4x32GB configuration, hammer test, or rowhammer in linux will overflow ECC error counters and reboot the system. This does not happen in any other configuration with 2 or 3 sticks of this RAM installed. I suspect BIOS is not setting up TRR/pTRR correctly when running 4x32GB. Will continue using this RAM for ECC in 4x32GB knowing this limitation.***UPDATE*** 5/19/22 : It should NOT fail the hammer test. I found that ffmpeg encoding let it throw errors slow enough to find the bad DIMM(s) with EDAC, while not rebooting the machine immediately. One DIMM fails after 3-5 minutes of ffmpeg encoding, another several hours. Ordered a replacement, now all tests are passing and everything seems good.

UPDATE: Tightened timings. I've been running mine perfectly fine for over a month at DDR4-3600 22-22-22-52-1T 1.35V after passing 4 passes of memtest86+. Basically stock SPD 3200 timings at 3600 at 1.35V (up from stock 1.2V). I may try tightening by 2 again.There isn't really much choice if you need relatively fast DDR4-3200+ ECC UDIMMs for AMD TRX4/TRX40 Threadripper platform, as ECC RDIMMs and RLDIMMs are not supported. 8x 32GB will max out maximum supported TRX4/TRX40 platform capacity of 256GB. These come with default SPD of DDR4-2666 if you boot on Auto DDR4 parameters in your BIOS. You can then increase memory to DDR4-3200 in your BIOS. Make sure to disable XMP/AMP memory profile support in BIOS as mine wouldn't POST with it enabled at DDR4-3200. At DDR4-3200 SPD timings are 22-22-22-52-1T 1.2V. I'm running mine perfectly fine at DDR4-3600 24-24-24-56-1T 1.35V passing 4 passes of memtest86+. I don't recommend going above 1.35V because newer higher-density higher-capacity lower lithography memory cells have lower Vmax and these come with no heat-spreaders. I have super-fast binned Samsung B-die non-ECC 16GB dual-rank DDR4-3200 14-14-14-34-1T 1.35V modules I ran at DDR4-3600 16-17-17-17-1T 1.45V and memtest86+ benches these NEMIX modules 15-20% slower in throughput and 20% higher latency than my super-fast binned Samsung B-die kit at DDR4-3600. I use NEMIX ECC RAM with AMD Threadripper 3970X on workloads that take hours to days to complete and eat up a lot of RAM (currently up to 90GB allocated out of 128GB, my previous 64GB capacity caused heavy memory swapping and SSD thrashing). So far I have no problems with this NEMIX ECC RAM. If you run lengthy workloads that require in excess of 64GB, ECC UDIMMs is a no-brainer requirement.