I don’t think you’ll be able to get much better of a deal than 1920x + x399, but definitely something to consider.
A little of A a little of B.
To explain this in detail would take a lot of writing. I wrote an article in '16 about this here: The Pragmatic Neckbeard 3: VFIO, IOMMU and PCIe
You can bypass it with the PCIe ACS Override Patch, which you’ll understand after reading the top post on that thread.
IOMMU Groups are more of guidelines* than actual strict rules.
*in most cases. Occasionally there is an actual physical limitation, but that’s only on some threadripper boards (as far as I’ve seen) and you can usually change that with a BIOS setting.
This should work. Not sure if this exists, but I wouldn’t be surprised if it does. You really only need 1x USB 3.0 port per VM to get the bandwidth you need for audio and Keyboard/Mouse
You could also do something like this:
Most Threadripper boards have multiple M.2 slots, and if you can make do with SATA only, you’ll be able to use those lanes.
It’s worth noting that most threadripper boards do not support bifurcation which means you cannot use a PCIe “splitter” to take a 3.0 X16 slot and turn it into 2 3.0 X8 slots and run two GPUs off it.
I’m pretty sure the Zenith extreme x399 supports bifurcation on all the pcie x16 slots.
I’ve got an x399 Taichi. I’ll check it tomorrow for support.
You should only need x4 for all the GPUs you have in your arsenal. If you were doing something with a 1080 ti or a 2080 ti, I’d recommend 8 lanes, but 4 should be fine for the cards you’ve got there.
They’d look something like this:
http://www.ameri-rack.com/ARC2-PELY423-C7_m.html
Now, the only other issue I can see here would be a case. You’ll have to do some custom fab work to find all these devices a home on the back of whatever case you choose.
It’s nearly 2am here. I’ve got to get some sleep. I’ll catch up with this tomorrow.