@wendell Could you please lift the veil around ECC and the 8700G?
(I promise to still watch and comment on upcoming videos regardless)
Due to AMD’s (willfully sloppily wrong?) early spec page that started this thread and has recently been changed online information about this specific feature is now effectively tainted. 
This entire launch has been a nightmare. AMD switching specs at the last second, updating others after the fact, and entirely missing the skin temp issues dragging performance down until reviewers caught it.
I am not feeling good about ecc udimm support so far, going to try another udimm kit and different kernel version. Theoretically the pro CPUs support it but I’ve only found one a620 board for industrial use cases that calls out ecc support.
Still testing
I’ve removed references to ECC support from the TPU pages for now since AMD has done the same on their site. If you can confirm any support at all I’m willing to reflect those findings on our database entries with notes on what does or doesn’t work.
No ASUS AM5 motherboard hiding somewhere? Most of them have the same ECC functionality as their AM4 predecessors.
Has anyone confirmed if the x8 in the x16 slot can be bifurcated to x4x4, or if that’s even possible? I wanna put 5 m.2s on the Aorus Ultra B650i and I can’t find any concrete answers in their documentation.
Couldn’t find an answer to that, yet. But my completely subjective gut feeling says that it should be possible.
As soon as it is confirmed that ECC wasn’t cut away by AMD I’m getting a 8700G for experimentation. If it doesn’t have ECC I have to wait for the PRO variant, probably called 8750G.
Sorry to not be able to give you an answer with an actual foundation.
It’s all good, appreciate the insight. I ordered an 8700G anyways (who needs to pay rent) and will be testing it with that board, a Asrock B650M HDV and a ASUS Strix B650E-F and will hopefully have answers Friday. Someone’s gotta find this stuff out.
There maybe is still a little bit of hope left:
For reference checked AMD’s spec website for the Ryzen 7 PRO 5750G and there AMD also does not mention ECC at all while this specific APU model obviously supports it.
So I just want to confirm a thing here which might help make inferences on memory situation if we can make inferences to past apus?
The B650i Aorus Ultra does in fact, bifurcate the x16 slot (effectively x8) into x4x4. So the 5 m.2 apu build is still a possibility.
Unfortunately that’s not wise: The separate IO Die from the regular Ryzen 7000 CPUs has different PCIe capabilities compared to the Ryzen 8000G APUs that use a monolithic Die for everything.
For reference see Ryzen 5000 CPUs and AM4 5000G APUs that share similar design differences:
But unlike the current situation the Ryzen 5000 and 5000G models have the same amount of PCIe lanes but the APUs can’t do x4-x4-x4-x4 with their main 16 PCIe lanes. Only x8/x4-x4 or x4-x4/x8 is possible, for some reason there is a max of 3 different PCIe Devices the 5000G APUs can address with their main 16 PCIe lanes.
Is there something like this with the Ryzen 7000 and 8000G CPUs and APUs? No idea!
A more unknown is the support factor on other OEMs, some boards don’t like quad M.2 PCIe cards and that makes creator boards a necessary extra cost. APU looks better these days.
No APU so far could do Quad M.2 cards, even the 4000G/5000G with the same amount of PCIe Lanes (be it Gen3 instead of Gen4) as the Ryzen 3000/5000 CPUs, the 8000G won’t as well since it only has 8 PCIe Lanes for its large PCIe interface. But with simple x4-x4 bifurcation and the other two x4 M.2 PCIe slots you should be able to hook up four x4 NVMe SSDs in total to CPU PCIe.
Are there any guesses to as whether the graphics “stack” will be in separate IOMMU groups? I’m aiming to build a new HTPC with the 8700G, and I’m kinda hoping I’ll be able to pass through the graphics to a windows guest on a KVM box.
If this is purely mobo dependant - what are manufacturers (and/or their product lines) with a good track record when it comes to providing virtualization-friendly IOMMU groups?
I strongly doubt that any answer with real weight can be given at this time: From AM4 on we know that IOMMU behavior can suddenly change from BIOS update to BIOS update and the launch of Phoenix feels like there are going to be quite a few BIOS fixes coming. :-/
I have 4x NVMe on a 5000 series APU just using iGPU + bifurcation cards
I haven’t seen bifurcation on an APU. I’ve always used bifurcation cards.
I was also about to do this, and I look forward to your response. What ram did you end up going with?
Just to be sure, you aren’t using 4 NVMe SSDs in a bifurcation quad M.2 carrier, correct?
Only 3 NVMe SSDs are operated in up to two PCIe-to-M.2 adapter cards in the regualar PCIe slots and 1 NVMe is installed in the separate motherboard M.2 NVMe slot - at least this is the only configuration I ever got working with a 5750G.
Hmmm…
I’m kinda new to this but shound’t 4x4 bifurcation be possible, for example 8700G on a Proart B650 Creator?
Can someone sanity check me?