A while ago when I was trying to configure a VM on my system the VM using a GPU in a PCIE slot that went through the south bridge there were extreme graphical glitches (anything 3d wouldn't show up and some windows had strange white lines through them) is this a known problem (gpus on the south bridge not working properly) I don't have any xml files (the server has since been uninstalled) just wondering if there was a fix I didn't know about.

I am experiencing a similar issue. Haven't checked which bridge the pci runs on tho..

 

I have three GPU's installed, pcie1: gtx 710 for unraid. pcie2: gtx 1060. pcie5: gtx1070.

 

the 1070 is used for a windows 10 vm and works great.

 

I have tried the 1060 with an ubuntu vm which also works great, but when used in a windows 10 VM I get this graphical issues you mentioned.

 

When the vm boots there are no apparent issues and I can run furmark stress tests without issues. but once I start using chrome or trying to launch a game, it all goes flip mode.

 

 

which motherboard?

 

mine was a gigabyte z97x-ud3h-bk

Asus x99-E WS motherboard.

 

I think I narrowed it down a little bit more. When running two win10 VM's at the same time, the VM with the GPU in the third PCIe slot got the problems. This was the case with either the 1070 or 1060.

 

What is weird is that it didn't matter if both VM's were running or not, as long as the GPU was connected to the MB, the issue occurred.

 

I changed the machine type to Q35 and now it works well.

 

 

ya exact same issue, wish I had known that fix a year ago    I wonder why that works?

 

also, If you can, use the igpu instead of a 3rd card