Problem using more than 2 GPUs

[hafager]

I have a setup with 4x Nvidia GeForce 1080 GTX and want to create 4 virtual VMs, each with one dedicated GPU. unRAID recognized all the GPUs and list them like this:

    [1] NVIDIA GeForce 1080 GTX (03:00.0)

    [2] NVIDIA GeForce 1080 GTX (04:00.0)

    [3] NVIDIA GeForce 1080 GTX (81:00.0)

    [4] NVIDIA GeForce 1080 GTX (82:00.0)

But only the VMs dedicated to #1 and #2, will work. The ones dedicated to #3 and #4 only show black screens. I have tried mixing up the CPUs assigned, but it doesn't affect the outcome.  I have also swapped the GPUs around, turns out the VMs using GPU #1 and #2 always work, while the other doesn't.

 

Any help is appreciated.