Problems with multiple monitors in Ubuntu 13.04

[caperry at edolnx.net]

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.

  -Carl