Xnp-ng and Gpu passthrough

Hi was wondering
I no you can gpu passthough on xnp-ng but how successful is it with a nvidia gtx 980ti to a linux vm or win vm as i use blender alot and would of load the rendering to the vm

I have never done it, but it is possible. It is not currently and is not likely to be supported via the web GUI though.
https://xenserver.org/blog/entry/pci-pass-through-on-xenserver-7-0.html

Thanks Tom for the reply

I found that very useful but came across a weird problem of which i might be doing something wrong.
This is my understanding
As xcp will grab and use the gpu in dom0 i decided to add another gpu to pass through thats when the fun starts?
I shutdown the server and installed 2nd gpu, upon restart it boots but hangs not sure why so tried another gpu and the same thing?
Am i doing something wrong when adding more hardware to xcp? Or missing some steps out?