Modeline for one monitor in twinview setup.

So I have a macbook pro retina that is running ubuntu 13.04.
I have driver version 319.17.

My problem is that I’m using an dell u2711 monitor using the HDMI interface.
this is a 2560x1440 resolution monitor but it only reports 1920x1080 as largest resolution in the EDID information when HDMI is used.

I want to use the modeline
Modeline “2560x1440_30.00” 146.25 2560 2680 2944 3328 1440 1443 1448 1468 -hsync +vsync
with this monitor to get the native resolution.

I have a config that starts two separated servers one for the internal LCD and one for the DELL monitor that can use this modeline and thus the native resolution.

however this is not a configuration that can be used for work. I tried xinerama but now ubuntu (unity/compiz) failed. And I have so far not found a way to make a config that used twinview and was able to use that modeline change.

I attached the config that has the correct resolution on both monitors.
if anybody knows how to make this work in twinview I would be really happy.
xorg.conf.txt (2.8 KB)

Just use xrandr for the multimonitor setup and use xrandr to add modelines, too.
Take a look at man xrandr and the --newmode and --addmode options.

Same problem. xrandr only works in the config I posted. Once I try to make a twinview setup it fails.

I dont understand how to make the config so that I can add modelines that is not in the edid from the monitor once twinview is activated.