I've been trying to passthrough my gtx 780 to a blank windows 10 vm. The set up works relatively well, but once the nvidia graphics drivers are installed, connecting a second/third monitor causes the entire operating system to suddenly die in performance (see this thread for the exact problem https://forums.geforce.com/default/topic/676979/gtx770-dual-monitor-setup-horrible-stuttering-lag-low-fps-and-screen-tear-/ ).

 

For me, the problem starts as soon as I plug a second monitor in and persists after the monitor is unplugged. After rebooting, the graphics are scrambled I have to set it up again. Uninstalling the nvidia drivers fixes the problem, but obviously that isn't a proper solution. I've tried disabling all the nvidia services but that again didn't help. Not sure if it is relevant, but rdp also runs super laggy.

Just wanted to chime in on this thread and let you know this doesn't appear to be an unRAID or VM related issue.  You are better off chiming in with NVIDIA to get to the source of this issue as it seems to stem from their side.

I've run a kvm vm on the same hardware on fedora and it was working perfectly well, I think something in unraid is messing with the graphics card passthrough but I don't understand enough to know what it could be.

fixed by enabling compatibility mode for multi-monitor gpu acceleration now I just have to get the virtio driver working.

fixed by enabling compatibility mode for multi-monitor gpu acceleration now I just have to get the virtio driver working.

Told yah it wasn't unRAID!!

I'm not sure entirely what is going on, but my dpc interrupts are really really high and the cpu usage on the os vs unraid is really disproportionate. The system is still a little laggy - it turns out enabling msi interrupts completely fixed the graphical problem but now it seems to still be a little laggy occasionally.