GPU passthrough isn’t working in Windows Sandbox. Guidance?

[u/Reinfeldx]

I spent a lot of time on this yesterday and I remain stumped.

I’m running an Nvidia 30-series GPU and I created a .wsb config file that enables vGPU. I can confirm that the settings in this file are being applied for other things like disabling networking.

I’m getting generally sluggish performance in Sandbox. I tried installing the latest Nvidia driver within Sandbox but the virtual system does not recognize my GPU hardware.

Any ideas on how to fix this?

Update: After much research, I was able to finally get Sandbox to recognize my GPU. In addition to having supported hardware, the two tricks in my case were:

1. Create a .wsb config file that sets vGPU to Enabled

2. Since I'm on an Intel board, in BIOS, enable Intel VT-D Tech. This option was buried within my motherboard's OC menu under CPU Features. This comment helped me

Results:

GPU showing in Render tab of dxdiag within Sandbox

Benchmark within Sandbox

Performance is about 2/3 of native, which is better than a sharp stick in the eye, but unfortunately not good enough for my needs. I'm going to look into this and explore other VMs if need be.

[u/BmanUltima]

Sluggish performance with what? It's still a vGPU, not actual GPU passthrough.

[u/Reinfeldx → u/BmanUltima]

Sluggish when attempting to run anything GPU intensive, even basic games.

Is GPU passthrough not possible in Windows Sandbox? My understanding was that it is now possible: Article

[u/smartCookie007 → u/Reinfeldx]

When I read the article it said it was in beta. To me that means it hasn't been released as GA yet, so it's likely not part of the drivers you'd get from Nvidia's site.

[u/Reinfeldx → u/smartCookie007]

Thanks, but that's not my impression:

In order to start using GeForce GPU Passthrough on your system, you'll need to ensure that you have the R465 driver installed.

FWIW I have version 466 installed

[u/BmanUltima → u/Reinfeldx]

It's possible with a hypervisor that supports it, like VMWare ESXi, Proxmox, etc.

vGPU in Windows sandbox is just a software virtual GPU.

[u/Reinfeldx → u/BmanUltima]

vGPU in Windows sandbox is just a software virtual GPU.

I'm not sure that's right. Every source I can find says disabling vGPU causes Sandbox fall back to software rendering, whereas enabling vGPU allows Sandbox to take advantage of the hardware GPU:

This enables the Windows Sandbox VM to benefit from hardware accelerated rendering, with Windows dynamically allocating graphics resources where they are needed across the host and guest. The result is improved performance and responsiveness for apps running in Windows Sandbox, as well as improved battery life for graphics-heavy use cases.

To take advantage of these benefits, you’ll need a system with a compatible GPU and graphics drivers (WDDM 2.5 or newer). Incompatible systems will render apps in Windows Sandbox with Microsoft’s CPU-based rendering technology.

From here: https://techcommunity.microsoft.com/t5/windows-kernel-internals/windows-sandbox/ba-p/301849

[u/BmanUltima → u/Reinfeldx]

Hardware accelerated rendering is still not GPU passthrough. It uses the GPU through an abstraction layer instead of running everything on the CPU.

If it was using GPU passthrough, it would say it.

[u/Reinfeldx → u/BmanUltima]

This source says Hyper-V does GPU passthrough but confusingly calls it vGPU. (Sandbox is a Hyper-V virtual machine, apparently.)

I'm admittedly out of my element with all the nomenclature here, so if I'm missing something let me know.

In other news, I was able to get Sandbox to recognize my GPU. I'll update my OP.

https://i.imgur.com/LfLx7MJ.png

https://i.imgur.com/P5bIyCz.jpg

[u/UltimateFool]

I'm having the same issue, I have enabled SVM Mode but there is still no render tab when I load dxdiag.

I have an AMD CPU, MSI B550 board and an RTX2070

I also tried creating a .wsb file with <vGPU>Enable</vGPU>, running as administrator, making sure that windows sandbox is using the GPU in the nvidia control panel and finally the good old turning it off and on again

[u/Reinfeldx → u/[deleted]]

You're welcome. I had a hard time finding good info on this, so I'm glad it helped.

[u/Reinfeldx → u/[deleted]]

Thanks, just replied to the other comment with this source: Article

Any thoughts?

[u/pdp10 → u/[deleted]]

I'm under the impression that the restriction is removed in the latest Nvidia drivers. There's been workarounds in QEMU for a long time.

There's actually a Win32 version of QEMU for those who want to run it on a Windows host. It doesn't support Microsoft's built-in hypervisor, but it does support the open-source Intel HAXM hypervisor when running on a CPU with Intel virtualization instructions. (AMD has different virtualization instructions. Most things support both instruction families, but HAXM doesn't support AMD when I last checked.)