Has any of the early birds had a chance to test Zen4 with VFIO ?
It sounds like all the new AMD CPU’s will have integrated GPU - which would make for a killer VFIO setup!
We still need proper IOMMU groups though - anyone know how that look on the x670 / b560 boards?
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It’s very exciting and I can’t wait for someone to fully-populate an X670 board, enable IOMMU, and dump the groups from Linux for us to peruse. I’m particularly interested in how the devices attached to the various chips in the chipset will appear and if there’s a measurable latency hit for high-speed devices as you move further away from the socket. Like, please show me the QD1T1 write latency for a P5800X attached to a Ryzen 7000 IOD vs the first chip in the daisy chain vs the second. Inquiring minds need to know!
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Look forward to the first guy to show up with two Radeon RX 7900 XT plus one RX 7800 XT (or one RX 7900 XT dependent on slot spacing…)
All three running at full bus speed without compromise. I believe it’s achievable with MSI X670E Godlike or ACE as all three slots on these two boards are connected to CPU as PCIe 5.0. So far I think it’s only available from MSI.
Really exciting time!
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Alternatively, look forward to the first guy to show up with two Radeon GPUs or two RTX 40 series on ASUS X670E ProArt.
I believe ProArt is one of the few boards including USB4/Thunderbolt and yet not at outrageous price.
Really exiting moment.
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That’s awesome and I’m glad to see one mobo maker doing interesting things with this platform. Neither Asus, ASRock, nor Gigabyte have anything like this yet. Thanks for sharing.
Hopefully RX 7000-series is Gen5 native. AMD tends to be ahead of the curve on these things.
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While I’d be lying if I said I wasn’t excited to see the capabilities of PCIe Gen 5 on all the things, I also really hope to see some more workstation-type boards breaking things out, say using on Gen 5x4 to Gen3 8x/8x to let older AICs use their full bandwidth for example with PLX switches and such and hope those play nice with VFIO. Partially because I still have a bunch of older Gen3 cards and drives that are still good that I’d like to use alongside a full-on PCIe5 gpu and see just how much we can pack in to one ‘desktop class’ system
ive tried looking, but cant seem to find the info. how many PCIE lanes does the 7950X have?
28 PCI-E 5 lanes, AM4 had 24 lanes.
16x GPU (or 8x8 or 8x4x4 split)
4x M.2
4x Chipsest
4x GPP - General Purpose, usually M.2, thunderbolt/USB4 or an extra PCI-E slot.
Note that the B650 and X670 chipsets are both PCI-E 4 to the CPU - so a future chipset could make this PCI-E 5 to the CPU, doubling bandwidth.
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ok, so it would be possible to do a dual GPU build with passthrough with a 7950X.
I put the iommu groups in my videos, pure cpu lanes do get their own groups.
more later
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Hi Wendell,
have you tried to run something like a Mellanox ConnectX-3 over PCIe x4 via chipset?
I am still using a Threadripper 2920x and Threadripper Pro is too big for what I need and also too old for the money…
I need a new home for my 6800XT, Intel P4618 and Mellanox Connect-X3 pro and I’m not sure if I can get by with a consumer platform, and what I’ve heard 128GB should also not run so well.
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You’re da’ man @wendell 
I’m looking forward to that - seems like this might be the perfect platform for VFIO!
But typical ASMedia means bad grouping on chipset lanes?
That was my first reaction when ASMedia was the supplier for the X670 chipset.
Hint hint, if the community can provide @gnif access to Ryzen 7000 and the associated hardware, VFIO support will likely come soon 
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ACS patches for the X670 chipset would be what I’d focus on immediately. There’s no way an ASMedia chipset will have proper IOMMU separation.
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Well TBH its not a guarantee for actual support, more like having the devs have early-ish access the hardware, the sooner they can look into this and see if they can implement it and have possible workarounds.
Wendell released this video showing IOMMU groups on the ASUS ROG Crosshair X670E Hero. Everything from the chipset is in the same IOMMU group.
It’d be good to get some IOMMU dumps from other motherboards to see if this is a once off thing, or shared by all X670 chipsets. IIRC IOMMU groups on X570 varied by model and manufacturer.
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It’s all X670 boards because ASMedia made the chipset.
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Perhaps people should start making noise and get it heard by AMD & ASMedia.
The client IOD has proper IOMMU groups which is indicative that AMD has no intention to deliberately disable the feature on consumer processors.
The lack of proper IOMMU group separations on the chipset is likely not enough requests heard by both AMD & ASMedia. It’s kind of a feature done once and get carried forward to future chipsets.
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