How to set modeline under xorg server 1.8.0

Robert Thompson xorg at
Fri Jun 11 15:13:23 PDT 2010

On 12/06/10 06:57, Another Sillyname wrote:
> On 11 June 2010 12:56, Robert Thompson<xorg at>  wrote:
>> On 11/06/10 18:54, Another Sillyname wrote:
>>> On 11 June 2010 02:26, Another Sillyname<anothersname at>
>>>   wrote:
>>>> Hi
>>>> I have a setup which I've just upgraded to Fedora 13 with Xorg server
>>>> 1.8.0.  The setup has a Quadro FX 3400 card with an IBM T221 3840 x
>>>> 2400 monitor.
>>>> Under previous iterations of xorg i've output to the monitor as a
>>>> dualhead setup using 1920x2400 + 1920x2400 and it's worked pretty
>>>> well.
>>>> However under the new version of Fedora the xorg.conf file now gets
>>>> re-generated every reboot using udev to detect devices if I've
>>>> understood the docs properly.
>>>> Unfortunately the display is getting detected as a 3840x2400 screen
>>>> and is being output to at the wrong refresh rate, 50 hz rather then 25
>>>> hz, at least according to xrandr -q, and as a result the screen is
>>>> blank.  The xorg session is running however as I can vnc into it and
>>>> it's running fine.  I am using the nvidia driver from rpmfusion.
>>>> Given that xorg.conf is re-written every reboot how can I add both a
>>>> modeline and dualhead type config so that it 'sticks' after a reboot?
>>>> Thanks in advance.
>>> As a follow up to my earlier mail I've found that you can now put the
>>> xorg.conf in /etc/X11/xorg.conf.d and it will get read from there so
>>> that's solved that problem.
>>> My new problem is slightly different in that as the display is treated
>>> as two screens how do I get the screen background and panels to spread
>>> across as a single screen?
>>> i.e. at the moment my desktop background is shown as two identical
>>> images one on each screen, what I want is one background image spread
>>> across both screens.  Also any panels are limited to one screen rather
>>> then being spread across both screens.
>>> I know ATI had a concept called 'Big Desktop' for these situations but
>>> I could never get it working, does anyone have any ideas or
>>> workarounds to get it working now with an NVidia card?
>>> Thanks in advance.
>>> _______________________________________________
>>> xorg at X.Org support
>>> Archives:
>>> Info:
>>> Your subscription address: xorg at
>> look for a "twinview" setting in your nvidia-settings panel, if having
>> trouble finding the nvidia-settings via the GUI just open a terminal and
>> type "gksudo nvidia-settings" and you are operating a better instance than
>> you get from the menus in the (gtk) GUI anyway, at least after re-entering
>> your password (provided you are member of wheel).
>> (in GUI should be "System->Administration->NVIDIA X Server Settings", in
>> there  should be "X Server Display Configuration", look for button
>> "Configure..." to right hand side - this gives you a situation where the
>> picture you are saving by pressing enter after pressing 'printscrn' is the
>> full width of both displays sum width.)
>> twinview is the closest I have seen to what you are asking for, is it
>> available to you?
> Hi Robert
> Twinview gives you the two duplicated desktops.  I'm looking for a
> 'Big Desktop' mode where the driver treats two displays as one
> complete desktop.
> Regards
That's odd, I'll double check at work when I get there in about an hour 
and a half but from here I'd swear I've got our electronics engineer on 
a dual monitor setup using twinview which gives him a desktop 3840 
pixels wide by 1080 high covering two matched monitors set at 1920x1080 

When he presses 'prntscrn' (Ubuntu 10.04, NVidia driver) he gets a PNG 
that is 3840x1080 where-ever he chooses to save it - will repost from 
work after verifying this, but he can also spread anything (window type) 
across both displays.

Anyone else wanna let us know what they get when they choose 'twinview'? 
(*And restart-x!)

More information about the xorg mailing list