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I am planning to build home workstation for gaming / virtualization based on subj.

According to the 2990wx topology (i.e. here https://www.gamersnexus.net/news-pc/3350-threadripper-2-specs-price-topology-die-arrangement) I plan to have two KVM VMs for gaming with 4(8) pinned cores (eventually with 8(16) with a performace hit, but 4 should be fine at this time), dedicated memory (based on the memory channel related to particular chip) and one 2080ti passed through to each VM. I am hoping to run mentioned gaming machines simultaneously with minimal performance hit as both of them will use different memory channels and PCIe lanes and they should not need infinity fabric to be involved in memory / I/O access.

But.

I took a look to the documentation of the Zenith Extreme x399 MB in order to find out how memory channels and PCIe slots are wired with 2990wx CPU (better said dies) but I was not able to find such information there neither anywhere else on the internet.

Now I will be just guessing and I will be glad if somebody can confirm that it is like this:

Hopefully, memory channels are wired as anybody would expect so cores 0-3 (0-7 respectively) have direct access to DIMMs plugged to A/B channel slots and cores 16-19 (16-23 respectively) have direct access to DIMMs plugged to C/D slots. This should be fine.

But I am more interested in PCIe wiring.

From the documentation, there should be x16 x8 x16 x8 PCIe lanes available on connectors from the top to bottom. As 2990wx has 2 x 16 + 2 x 16 lanes in total I would like to believe that die 0 (cores 0-7) are directly connected to two top PCIe connectors while the die 1 (cores 16-23) is directly connected to two bottom PCIe connectors. I also believe that the rest of 8 lanes which are not available on connector 1 or 3 respectively are used for other devices, such as M.2 so each die should also have direct access to dedicated M.2.

As there are 3 M.2 slots on the MB, I believe the third slot is using PCIe lanes from chipset, not from CPU so it will be bit slower.

Maybe I am completely wrong and everything is software configurable instead of hard wired so BIOS takes care of proper configuration of each NUMA group with memory/PCIe channels. I just would like to know if the scenario I am planning to use is possible so the single PC box will behave like two gaming machines.

For those interested what I'll be doing with the rest of the memory and cores I'll be using them for other windows/linux virtual machines related to my work (while at least 1 gaming machine will be offline).

Thanks for help

Thanks to guys on ROG forum!

https://rog.asus.com/forum/showthread.php?107210-Zenith-Extreme-x399-2990wx-NUMA-groups&p=750011&posted=1#post750011

I was hoping that at least one M.2 will be connected through the chipset so I'll be able to passthrough 2 SSD's to gaming machines directly what is not the case but never mind, I'll use virtio storage for them.