GPU for KVM and QEMU?

After @wendell's great windows emulation video and write up, I'm looking into a new build to accommodate such a configuration.

I've been shopping for graphics cards and browsing this post regarding hardware mods to change device IDs. The following possibilities seem the best:

  • Gtx 690, with it half modded to be a k5000 or grid k2.
    -- Would it be possible to only pass one gpu to the vm?
  • Mod the 680 I already have to a k5000 or k2, and add a second card.
  • Get a pair of r9 380xs.

I'm really looking for gpu and cpu performance for both platforms on a single machine. So a dual socket 2011 with something like a pair of e5-2643 v2s(6-cores @3.5Ghz) and 32gb ram is what I'm looking at. Considering the easier route to pass an amd gpu to a vm, and the benefits of having a "k5000", gpu wise I am just looking for a configuration that could push through encoding and 4k gaming on mediumish settings. The more convoluted and sketchy the better.

What are your genius recommendations?

Go R9, its so much easier to set-up with a a pair of AMD cards.
Also you do not need a dual CPU build, 1 CPU will do, get an 8 core, allow 4 for host 4 for guest.
For RAM allow guest 16 and other 16 for host.
You will be fine there but no need for dual socket just go for more cores also 1 Physical Core does not exactly mean 1 vCPU core, you can allocate multiple cores to 1 physical CPU core as long as you don't peg it 100% all the time.

I used to run a passthrough with the nVidia 680 modded, I had two of them in my old Intel gaming rig, and it definitely worked. It was a hell of a job to get it working though, but a lot has changed in the last 4-5 years. From my experience though, I can definitely confirm that it's a hell of a lot easier to get things working on an AMD system. I mainly use AMD because of the trouble free virtualization, even though lately Intel seems to have caught up a little, there is still the matter of Intel not succeeding in producing any functional Beignet, and Intel not being able to produce proper power management modules until about a year after the hardware comes out. I've always been a great fan of the Intel Atom platform, because it's awesome how little power it requires for a pretty robust platform if used correctly, but Intel has pretty much kept early adopters standing in the cold for about a year, and it's still not entirely complete. AMD hardware might be older, but it's entirely supporting all virtualization functionality on almost all AMD and AMD-hardware-equipped OEM products across the board, for often obscenely low prices.