[Nouveau] Quad head graphics card.

[Ilia Mirkin]

On Thu, Jan 23, 2014 at 6:24 PM, Grzegorz Sójka <gs at sojka.co> wrote:
> On 01/23/14 23:12, Ilia Mirkin wrote:
>>
>> On Thu, Jan 23, 2014 at 4:56 PM, Grzegorz Sójka <gs at sojka.co> wrote:
>>>
>>> Hi there,
>>>
>>> I have 4 identical monitors. So I decided to buy (not to expensive,
>>> around 100USD) quad head graphics card. I do not need anything
>>> particular. Only office applications, no gaming. The crucial thing is
>>> that I would like to be able to span a single window across all 4
>>> monitors. I found following cards:
>>> Nvidia Quadro NVS440
>>> Nvidia Quadro NVS420
>>> Both are actually dual GPU. Could you please confirm which one of these
>>> cards may be configured as a single quad monitor DISPLAY using nouveau
>>> driver? What about the binary nvidia driver?
>>
>>
>> I would avoid those if possible. Both nouveau and the nvidia driver
>> wil support them in a 4-monitor configuration, but there will be
>> issues, esp with nouveau. Not sure about nvidia.
>
> So, it would be possible to configure all 4 monitors as parts of one logical
> DISPLAY??
> Just clarify: At the moment I use two dual head ATI FirePro 2270 graphics
> cards. As a consequence I have two logical (dual-monitors) DISPLAYS and the
> problem is that I'm not able to span a single window across more than 2
> monitors.

There are 2 ways of dealing with that (neither is nouveau-specific):

(a) You can use PRIME to render on one GPU and use the outputs on the
other gpu to display said rendering. This is possible using xrandr 1.4
and Xorg 1.14.3 or later.
(b) You can use Xinerama to create a virtual screen on these. This
loses you xrandr and direct rendering.

Neither of these yields a particularly fast experience.

  -ilia