Subject: Multi-display on Multi-GPU support

From: Alexander GamePad <[email-masked]>
Date: Wed, 26 Jun 2013 03:02:21 +0400

Hello,
Now (on X) there is no good way to use Three-headed configuration with two
GPUs. There are only two bad ways:
- Creating a separate X session for each physical display (or for each
physical GPU, using TwinView on nVidia configurations). This doesn't allow
us use any interaction between X screens such as dragging windows or
drag'n'drop.
- Using Xinerama. This piece of old code is totally incompatible with
Composite extension and disables hardware acceleration as well. This is
obviously bad.
Another approach is using XRandR, but it broke the image with nouveau and
just didn't work with multiple nVidia GPUs using latest 319 drivers.
So now there is no way doing this on X (but it is working perfectly normal
on Windows!).

So, I wish to know if this feature would be implemented.

---

From: Daniel van Vugt <[email-masked]>
Date: Wed, 26 Jun 2013 10:16:14 +0800

Alexander,

I think you raise a good point no one has discussed yet. That is "how 
does Mir handle multiple (simultaneous) GPUs"? I think we should keep it 
in mind as a driver model evolves.

As for multi-display, that effort is already under way. And hopefully, 
eventually, it will play nice with multiple GPUs.

- Daniel

On 26/06/13 07:02, Alexander GamePad wrote:
> Hello,
> Now (on X) there is no good way to use Three-headed configuration with
> two GPUs. There are only two bad ways:
> physical GPU, using TwinView on nVidia configurations). This doesn't
> allow us use any interaction between X screens such as dragging windows
> or drag'n'drop.
> Another approach is using XRandR, but it broke the image with nouveau
> and just didn't work with multiple nVidia GPUs using latest 319 drivers.
> So now there is no way doing this on X (but it is working perfectly
> normal on Windows!).
>