A few GPU-Passthrough questions

Hardware Hub
1

Hey everyone, had a few questions to get a GPU passthrough setup with a Linux host and a Windows guest.

  1. What is the cheapest GPU that will be compatible? I have a single GTX 1070, but a i7 4930k that doesn't have an iGPU, so I'll need a second discrete card.

  2. One thing I've been confused about: do I need to dedicate a whole monitor for one of the OS's? as in: If I had 2 monitors, each monitor would be stuck with one OS? I hope that makes sense.

To me it doesn't matter which distro I use. I just want muh gamez and a proper bash environment.

Thanks everyone.

2

Any card should work, just Nvidia might require extra tweaking.
And yes you're dedicating a whole monitor so you'd want to have a second one, it's doable with one just by changing from i.e. hdmi to dvi input but it cuts you off the host.

3

GPU's need to have a specific kind of virtualization technology, right?

And thanks for the tip on monitors, good to know.

4

Nah the gpu itself doesn't need to have any specific features, since what's happening in passthrough is you're literally forwarding the component itself to the vm, no virtualization magic there.
The only thing to consider is nvidia for some reason doesn't like to run in a vm, but it's pretty simple to trick it.

5

1 -- probably a sapphire 7950 if you don't mind used. you can pick them up for like $75

2 -- there are like a billion solutions to this. I use a KVM switch, some people use synergy or VNC, others buy monitors that pripritize certain physical inputs so the screen switch is automatic.

easiest distro is still prolly arch

6

if it isn't new enough to have UEFI GOP, then it can make things a lot more complicated, so saying "any card whould work" is very misleading.

7

As far as I know (so, not very...) virtual GPU and passthrough are entirely different things. A passthrough is just exactly that, the host doesn't even know that GPU exists. A virtual GPU is shared between host and VM, like a CPU that is shared between both machines.

Passthrough is handled by the motherboard and CPU. You don't need any special card for that.

8

Really? Never heard that before, how does UEFI GOP even work? Google isn't providing any useful reason you need it for passthrough, the only reasonable find was one post stating you need UEFI GOP for passthrough or use GOPupd to work around it, but again, no additional info.
It's confusing because you don't need UEFI to passthrough stuff.

9

you don't, but that's what all the doc revolves around nowadays. Not a huge issue but one that can stop you if you've got older hardware.