AM5 ECC support£

ApplesOfEpicness wrote: I have managed to reach out to an AMD engineer, who has confirmed that the issue is on their end, and they are targeting a fix to release in AGESA 1004/1005. No ETA on when they will be available, but at least we know it is an AMD problem/

Many thanks for the update. So as of my understanding ASUS claiming official ECC support but it does not work currently and ASRock seems to have removed advertisement for official ECC support. Both are not supporting it currently in practice.

So if ECC support is going to be in future AGESA updates there is hope that all/most AM5 mainboards will support ECC in the future. ASUS essentially need to as they advertise ECC support and ASRock might be changing their minds as soon as support from AMD finally works.

So let's wait a bit for the upcoming AGESA releases and how mainboard manufacturers will support ECC. Perhaps you can perform the same test again after both manufacturers released updates.

ApplesOfEpicness wrote: Update from the engineer. The fixes are committed for AGESA 1005. They guess it will come out sometime in Feb 2023.

Good to hear, was about to need new PC-s early spring.

Those are all Registered DIMMs. Ryzen won't ever support them.

But I believe we'll end up with 64GB unbuffered DDR5 DIMMs at some point, just as we got 32GB DDR4 DIMMs some time after DDR4 became the major player. Asrock's spec page for X470 Gaming-ITX/ac still says max supported memory is 32GB (16GBx2), but I'm running mine just fine with 32GBx2, so there's that.

Back in the early days of DDR4, the only ECC UDIMMs I could find were 2133MT/s. Nowadays, 3200MT/s is the norm. So I actually want to wait for at least 5200MT/s JEDEC to become the norm for DDR5 ECC UDIMMs before I jump in.

I did some testing with the new BIOS and can confirm ECC is working. https://imgur.com/a/w2jNLNg

I am using these modules in the Asrock B650E ITX board: KSM48E40BD8KM-32HM. The way I injected errors is really janky and I don't recommend doing it if you don't have steady hands/don't want to risk your hardware. I just took some tweezers and shorted a data pin to ground (287 & 286). I did the same with DDR4, as well as earlier last year to figure out that ECC wasn't working on AM5, so it wasn't too bad. The BIOS seems to have some ECC injection settings, but I have no idea if they work or not. Memtest86 doesn't seem to be updated yet so I can't try it.

Pinout for reference: https://media-www.micron.com/-/media/client/global/documents/products/data-sheet/modules/unbuffered_dimm/ddr5/ddr5_udimm_core.pdf?rev=fdbd9476506c4e019360a5e402827caa