Best GPU for Passthrough

Okay so I am getting a new GPU soon to replace my 6870, And I am looking for a reasonably powerful GPU (Around 3GB VRAM) that is also known to PCI Passthrough so I can finally get rid of my Second partition and run a tweaked version of Windows in a VM.

I plan on using maybe Arch or I may try OpenSUSE factory (Havent tried that yet) although stability-bleeding edge would be better for me over Bleeding edge unstable.

also for Passthrough what driver is recommended? FOSS or can Catalyst do it yet?




Memory on your GPU does not equate it to being powerful. That being said, the PCI passthrough, from what I understand, is reliant on your CPU supporting VT-d (Intel) or AMD's version. The passthrough is done through your VM software and the driver simply does it's thing as it normally would in your VM.

That being said, you lose visibility of your bare-bone because now you've dedicated the GPU to your VM. You'll need to keep that 6870 around or if you have onboard video, you'll need to configure that to work.

Just sharing my understanding of it, hopefully it helps in some way and I'm not totally wrong...I've been looking into this, myself but have realized that I'll need some money, first.


Yeah I know, but I was looking at maybe a 7970 due to drivers, also my CPU has VT-d but I tried this before with my 6870 and iGPU and it never worked 

Just thought I'd give you a heads-up; I tried running RUST on Ubuntu 14.04 and Mint 17 with the latest Linux drivers x64 and latest beta drivers and had screen tearing out the arse. Flash videos tore and GPU intensive applications tore. After doing extensive research, AMD drivers suck on Linux.  I'm now waiting for Nvidia's 900 series as Nvidia nix drivers are next to on par with Windows drivers.

I'm running a Gigabyte R9 280X R1, 4670K, 8GB Gskillz, Samsung 128GB SSD just for testing the game.

He's asking about PCI passthrough. The only cards that can do this (with very, very few exceptions as far as I know) are AMD cards with the open source driver.

Ubuntu isn't the end-all, be-all of linux distros. It's just better marketed. If you want a good distro to game on with the proprietary drivers, try Manjaro and get as far away as possible from Ubuntu. You'll be a lot happier.

Yes, Catalyst is behind xorg right now, and Nvidia's proprietary drivers are not, there's no denying that. But for AMD there's always the option to use the open source driver for gaming. I'm using it and I am extremely happy with it.

Well I plan to use OpenSUSE factory, always loved the main distro, but I always had issues with it, maybe as bleeding edge open source it may work.

Also should I enable my iGPU and remove the GPU before install of the distro? because last time I couldnt bind my 6870 in virt-manager.


Yeah Ubuntu and its bases normally suck with drivers, I had no end of issues in Ubuntu 14.04 with my GPU, got to the point where X died completely and I couldnt be arsed to fix it, hence my love of bleeding edge.

Also I hear Nvidia drivers suck in Linux, more so the open source ones, and r9 280x wont be fully there yet, which is why I am tempted for a HD7K series.

But thats anyways, also a fix for your problems with flash, go in CCC and then enable the screen tearing option, works a charm :)

I'm aware that Ubuntu isn't the end-all be-all :)

What AMD card do you have? What is the performance like (FPS wise)? Is there screen tearing? I keep hearing "I'm happy with the open source drivers" but the games that are being played are indie titles or DOS emulators on old or very low demanding engines. I'm curious to know if anyone actually plays games at 1080p resolutions with present technological features or if they're all just goofing around...I'm not attacking you; however, I would like to hear some factual evidence that Linux is playing games well. I guess you could say, I'm calling you out :)


The R9 280X is a 7970 so I can't imagine it being too difficult to get them working the same way.

The issue with the fix for removing screen tearing is that it turns on Vertical Sync. Which then creates input delay--which is a big no-no with FPS games. I know it's a band-aid solution but I'm looking for actual fixes or distros that don't suffer from these issues.


Zoltan has said a couple times that Nvidia cards don't work good through a pass through, so I'd go with anything AMD.

True. I got off topic slightly as I was referring to the performance of AMD drivers on a bare-metal *nix system. not through pass-through :) My apologies for off-railing the discussion.


Sapphire R7 260x, the downclocked version (to 1050 MHz core clock, instead of the regular version which has 1100 MHz).

I'm playing right now Divinity Original Sin on Wine 1.7.25 (so directx 9.0). I suppose it's indie since it got crowdfunded, but it doesn't feel like an indie game at all.

Mesa 10.2.6-1, Xorg-server 1.16.0-16.


  • 1080p
  • Vsync triple buffering
  • Textures high
  • Models high
  • Anisotropic 16x
  • Shadows at ultra (no light shadows though)
  • Ambient occlusion and god rays

It's an RPG, with the combat turn-based, so yeah, it doesn't need to be as fast as a shooter. And I can't tell you any FPS values since I didn't find a way to enable it in-game but it's perfectly playable.

And like I've said, these are the open source drivers. The proprietary version will do better because the game was optimized for them (and the drivers for the game).

If you can't get Catalyst to work on Ubuntu, try Manjaro, trust me, it's leagues ahead of Ubuntu when it comes to gaming.

Oh, I haven't even tried to do a PCI passthrough on my computer yet. What I know about it is from different forums that I found while I was researching which motherboards support AMD-Vi.

I'll give it a shot when I get home from work. Thanks for the response! Much appreciated.

I forgot to mention that I'm running kernel 3.16.1 and that I have set the variable R600_DEBUG=hyperz. hyperz increases performance slightly, but isn't enabled by default because it causes tearing on some GPUs (source:

For future reference, you can make the variable enabled at startup by using the following methods:

  1. add the line "export R600_DEBUG=hyperz" (without quotes) in /etc/profile. You need root permission for this and the change is global (is applied to every user)
  2. add the above line to one of the following files ~/.bashrc or ~/.bash_login or ~/.profile, depending on the distribution. Pick the one that you have in your home directory. Create ~/.bashrc if you don't have any of the files above and add this line to ~/.bash_profile: "source ~/.bashrc" (without the quotes). If you are looking for them with the file explorer make sure you can see hidden files (the "." before the name means it's a hidden file).

I doubt Zoltan would really mean to say that, but maybe he dislikes Nvidia enough to do so - It's a shame nobody thought to correct him? There were a few workarounds years ago that were needed, but patches and such have helped things.

There's a saying in linux, "Time fixes everything."

Anyway, from my experience Nvidia GPU's work just fine running Quemu/KVM albeit with vfio-pci tweaks.

You should be getting on average around 95-98% performance with passthrough in my experience.

These days, I don't bother with passthrough because I don't dip under 60FPS gaming with Steam in Linux.

Which works for me cause I fucking can't stand using windows :P

I read the thread, and I was curious about the NVIDIA patches, do they work with the newest driver (340.32) or with the beta driver (343.14)? I am asking because the driver version mentioned is 337.88.

I'm not sure Ksajal, I've never looked into it as I wasn't using dual Nvidia cards.

I used Z77 with IGP (Intel HD4000) as my primary (host) GPU driver which if I remember correctly just needed Williamsons' patch for VGA arbiter support with the i915 driver.

I said it was virtually impossible to get nVidia cards to work with VGA passthrough. PCI passthrough is another thing. Sadly the distinction is not made by everybody.

For PCI passthrough, the card doesn't matter, unless it's the primary, because for a clean host system (which is the whole idea), the primary should work well with KMS drivers, and Nouveau isn't the greatest thing ever. If you need to game in linux (which is also the whole idea, e.g. Steam client in an unprivileged lxc), AMD GPU's are an obvious favorite, not only because of the better performance of the KMS drivers, but also because of the OpenCL performance, which is really nice to have. For those that won't game in linux (which is actually an intelligent option in my opinion, saves having to lxc the DRM-infested proprietary code, and Windows is a software console anyway, might as well run the Steam software console inside the Microsoft software console in the kvm container and keep all the malware crap together in the same hazmat dump), the built-in Intel graphics will do just fine if you don't need advanced GP-GPU functions, knowing that Intel Beignet is advancing slowly but steadily, so there will definitely be some kind of OpenCL acceleration going on, enough for things like faster preview rendering in photo editing software and things like that (unless you're going to edit bazillion pixel raws from a Hassie or something like that, but not many people shoot at over 20-25 megapixels anyway).

+1 on the "I can't fucking stand Windows" lolz...

That being said, I find XBoxOS worse than W7 but better than W8, so I'll game in W7 in a kvm container over using any other type of Microsoft gaming software or hardware console.

Okay so a R9 280 3GB should do fine, I dont need to get a 7970?