Problems with multiple monitors in Ubuntu 13.04

[Alex Deucher]

On Thu, May 9, 2013 at 3:58 AM,  <caperry at edolnx.net> wrote:
> On Thu, 9 May 2013 10:21:03 +1000, Dave Airlie <airlied at gmail.com> wrote:
>>>
>>> I have two 6450 cards in my Ubuntu 13.04 system with three monitors.
> This
>>> is
>>> a recent install with no binary drivers installed and no additional X
>>> ppa's
>>> installed. I can get X to display output on the primary monitor, and I
>>> can
>>> see all three in xrandr:
>>>
>>> Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
>>> HDMI-0 disconnected (normal left inverted right x axis y axis)
>>> DVI-0 connected 2560x1440+0+0 (normal left inverted right x axis y axis)
>>> 597mm x 336mm
>>>    2560x1440      60.0*+
>>> VGA-0 disconnected (normal left inverted right x axis y axis)
>>> HDMI-1 connected 1920x1080+0+0 (normal left inverted right x axis y
> axis)
>>> 475mm x 267mm
>>>    1920x1080      60.0*+
>>>    1280x1024      75.0     60.0
>>>    1152x864       75.0
>>>    1024x768       75.1     60.0
>>>    800x600        75.0     60.3
>>>    640x480        75.0     60.0
>>>    720x400        70.1
>>> DVI-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis)
>>> 475mm x 267mm
>>>    1920x1080      60.0*+
>>>    1280x1024      75.0     60.0
>>>    1152x864       75.0
>>>    1024x768       75.1     60.0
>>>    800x600        75.0     60.3
>>>    640x480        75.0     60.0
>>>    720x400        70.1
>>> VGA-1 disconnected (normal left inverted right x axis y axis)
>>>
>>>
>>> The second and third monitor are on (out of power save mode) but show no
>>> input. However, XFCE seems to detect them as I have two wallpapers
>>> stacked
>>> on top of each other, one at the main monitor's 2560x1440 resolution and
>>> one
>>> at a 1920x1080 resolution (see
>>>
> http://edolnx-public.objects.dreamhost.com/Screenshot%20-%2005072013%20-%2009_10_02%20AM.png
>>> ). Attempting to make any changes with xrandr causes X to crash with a
>>> SIGSEGV. Here's a log: http://paste.ubuntu.com/5640585/ Any ideas?
>>
>> You probably need to setup an xorg.conf like you always have before
>> for dual-card setups like that.
>>
>> It might be possible to make it work better if you plug two monitors
>> into the first card and one into second,
>> you'll be using GPU offload, so the second GPU won't be doing anything
>> more than displaying what the first
>> is showing.
>>
>> Dave.
>
> I've tried creating a basic config for multiple monitors, and now X crashes
> on startup.
> The config: http://paste.ubuntu.com/5646972/
> The log: http://paste.ubuntu.com/5646975/
>
> I thought it may be GLX, so I tried disabling that but got the same error.
> I also tried two displays
> on the primary card. That created output on two displays, but using xrandr
> still caused a crash of X.
> The monitor on the second card still had no output.
>
> Any other thoughts?  I've tried ATI and nVidia cards, and both yield
> similar results. I realize this is
> the ati driver list, but it may be an interesting data point.

You need to use the ZaphodHeads option in each device section to
assign which connector(s) you want to use with each instance of the
driver.

Alex