Passthrough - direct and remote?

[sonofdbn]

I'm trying to understand what passthrough means on a VM, in particular for a graphics card (GPU).

 

I get that the GPU can be assigned exclusively to a VM (while the VM is running). And my reading of various threads tells me that to get optimal use out of the GPU I should connect my monitor directly to the GPU with a cable. This would be my natural understanding of "passthrough". However, somewhere I got the impression that it's also possible to get at least some of the benefit of the GPU using remote access over Ethernet.

 

So, for example, if I had a GPU passed through to a VM, and accessed the VM using Remote Desktop or Splashtop, would I see any visual improvement? By improvement, I mean snappier desktop performance (not expecting bare metal performance); gaming capability would be a bonus, but not essential.

 

Also, would it be possible to get the benefit of the GPU audio out over remote access? Or do I have to be physically connected? (My motherboard doesn't have onboard audio.)

[Warrentheo]

Passthrough means that the card is exclusively connected to one VM, and the UnRaid host no longer has access to it... This means that it acts like any GPU would on any other computer... Without passthrough, you would boot to the UnRaid web gui interface only, then only have access to the "Remote" video card through the web browser interface...  The VM would have to have fake GPU acceleration driver installed (Not accelerated by the GPU) and then sent to the VNC interface...  Since your GPU horsepower never really gets used, most games wont even run, and the few that do will be unplayably slow...