GPU Passthrough ... finally!

Posted on Sun 23 July 2017 in Blog

21:07:17 12:27 That's when it finally happened. For the best part of 10 years I've been trying to get graphics passthrough working on my hypervisor, thus enabling the one box theory.

I'd taken two days off work, a long weekend. Planned to swap a 4TB drive out for a 3. This involves rebooting, a rare occurrence. I had left a passive gpu in from the last failed attempt so thought best to take it out as well as swap the drive. Figured its become traditional to throw a few hours every year at graphics passthrough. I did so.

I'd been thinking lately about the BIOS level and how its not taught and often overlooked these days...

I went in to the BIOS and disabled everything that sounded like a media extra. Deep rendering, HD Audio etc.

I booted up my test VM with the GPU attached. It booted. I installed the driver. Then the console screen went black, at this point it would normally crack into four screens, BSOD, reboot and fail to post again. It stayed black. Not black the screens off, black the desktop is showing. It wasn't. I looked over at the screen I did have plugged in. It had a windows login box on it. Via the console I tapped in the password. It loaded to a desktop. I was beside myself. A few clean reboots later and I still was.

Something I'd had as an idea nearly 10 years ago, a "one box" theory, that I'd spent countless pounds and hours on, spent the last several years working around the fact it would never be possible (without spending further thousands in one hit) had just happened.

Consequently I had no audio or USB pci cards laying around. An Amazon later I did, in the morning. I spent the rest of the evening adding more GPUs and configuring screens.

After adding USB 3.0 cards, USB sound and connecting to all my existing screens, hubs and other bits. I had a fully functioning virtual desktop. Watching films is fine. The sound lags by half a second it's barely noticeable. Played Rocket League, fine. I've literally been able to switch off a PC thus meaning I'm now running

One Box*

*(my pfSense is still a box, but a networking appliance so, discounted)