I'm on my phone so it makes it a little hard to elaborate on all the points, but I'll try to remember all of them.
Yes there is onboard video, it doesn't show in that list because - grepped for "Cypress XT" not "VGA". When I grepped for VGA, I got several screens of output and didn't sift through it thoroughly.
I have tried hotplugging and coldplugging different devices. Yes, I would assume that the host is trying to use one of the cards and that could cause a conflict. I just had a thought - would it be possible that the host is glomming on all the cards just because they are there? I should change my BIOS to boot the internal video first and use it as primary display.
When hotplugging, the host (dom0) was what panicked. When coldplugging, the guest (domU) either flashed the VNC terminal on and off repeatedly (when a single device was configured) or showed a black screen and froze (no networking or anything) when all cards were assigned.
Unfortunately development is kind of on hold because of time constraints (weekender) and because these fans at 100% are damn annoying.
I need to get the following list of stuff done:
Custom bracket - need to find a small fabricator near me
Copper bus bar - determine correct size, layout, and method of attaching conductors
PSU - figure out how to turn it on
PCIe 6/8 pin connectors - obtain a bunch and figure out how to hook them to the bus bars (ring/spade terminals? solder? clamp?)
Air channel/duct - needed so that the air doesn't escape past the heatsinks over the top - also a job for the fabricator - needs to be slotted so the upper level PCIe extenders can pass thru
Fan contoroller - wire it in once it arrives and set up the control software (to be written, coder is lined up for the job)
Damn, I wish it was as easy as throwing some money at it and putting it together like Legos.
Problem is, I'm kinda weak when it comes to the software and scripting/programming side of things. Once it's done, does anyone wanna buy it and have the distinction of owning the worlds fastest, most complicated GPU based rig?
It will need a 7KW power outlet and cooling.