You’d only need a main board with for x16 physical slots as PCIe x4 would be sufficient bandwidth for desktops.
You’re also not pushing the GPU’s power envelope, so one beefy or two smaller PSU’s would suffice. The AMD WX7000 series workstation cards don’t even have the extra PCIe power connectors (last time I looked).
I suspect these are more likely to be two or more machines though.
Four GPU’s with four outputs each would do it.
You’d only need a main board with for x16 physical slots as PCIe x4 would be sufficient bandwidth for desktops.
You’re also not pushing the GPU’s power envelope, so one beefy or two smaller PSU’s would suffice. The AMD WX7000 series workstation cards don’t even have the extra PCIe power connectors (last time I looked).
I suspect these are more likely to be two or more machines though.
Matrox makes some crazy multi-monitor GPUs that could do this without needing as many cards.
Here’s their 8-display version: