PCIe Splitter/Riser and IOMMU splitting

[RavyuS]

Hi,

 

I am interested in trying a 8 GPU VM setup with an i9-7980xe running 8 VMs with GPU passthrough. Unfortunately, none of the X299 boards have more than 4 PCIex16 slots, making this impossible without any external setup. I stumbled upon this PCIe Splitter/Riser by SuperMicro and thought it could work. My only question is, are the two GPUs attached to one PCIe x16 slot going to give issues in IOMMU splitting, using ACS Override?

 

I'm not sure how the chipset/mobo is going to recognise this setup. I'm fine if the GPUs run at x8 capacity as I'm not looking at very high-end gaming. Just need a single board 8 VM solution.

 

Edit: I did a little bit of research. Apparently I need to look out for PCIe Bifurcation support on motherboards in order for this to work. Assuming I can find one, will IOMMU grouping still be an issue?

 

Thanks!

Ravyu