30" Apple Cinema Display

[rfindler]

Hi all:

I'm having trouble getting my apple cinema display to use its proper resolution of 2560x1600. Instead, it seems stuck on 1280x800. I tried to xrandr to fix this, but I got stuck (as below). Any help would be appreciated!

The problem seems to come when I try to use --add-mode to say that my monitor is 2560x1600, but I included more of the transcript in case there is something useful there that I'm missing.

tia,
Robby

robby@taitung:~$ xrandr --fb 4480x1600
robby@taitung:~$ xrandr
Screen 0: minimum 320 x 200, current 4480 x 1600, maximum 4480 x 1600
VGA1 disconnected
DVI0 connected 1920x1200+0+0 495mm x 310mm
1920x1200 59.9*+ 60.0
VGA2 disconnected
DVI1 connected 1280x800+1920+0 641mm x 401mm
1280x800 59.9*
robby@taitung:~$ xrandr --newmode 2560x1600 348.50 2560 2760 3032 3504 1600 1603 1609 1658 -hsync +vsync
robby@taitung:~$ xrandr --addmode DVI1 2560x1600
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 149 (RANDR)
Minor opcode of failed request: 18 ()
Serial number of failed request: 27
Current serial number in output stream: 28
robby@taitung:~$ xrandr --output DVI1 --mode 2560x1600
xrandr: cannot find mode 2560x1600
robby@taitung:~$ xrandr
Screen 0: minimum 320 x 200, current 4480 x 1600, maximum 4480 x 1600
VGA1 disconnected
DVI0 connected 1920x1200+0+0 495mm x 310mm
1920x1200 59.9*+ 60.0
VGA2 disconnected
DVI1 connected 1280x800+1920+0 641mm x 401mm
1280x800 59.9*
2560x1600 (0x11f) 348.5MHz
h: width 2560 start 2760 end 3032 total 3504 skew 0 clock 99.5KHz
v: height 1600 start 1603 end 1609 total 1658 clock 60.0Hz
robby@taitung:~$

[rfindler]

Turns out what was missing was this line in my xorg.conf:

Option "AllowDualLinkModes"

in the Device section.

Thanks to Maarten Maathuis, who also leaves this word of warning:

On Thu, Jun 4, 2009 at 10:10 AM, Maarten Maathuis <madman2003@gmail.com> wrote:
> xf86-video-nv which i guess you're using doesn't unconditionally
> support dual link dvi. Some bios'es don't init it appearantly.
>
> There is an option to force it, but you could end up with a blank screen.
>
> Option "AllowDualLinkModes"
>
> Maarten.
>

[DomesDKG]

Turns out what was missing was this line in my xorg.conf:

Option "AllowDualLinkModes"

in the Device section.

Thanks to Maarten Maathuis, who also leaves this word of warning:

On Thu, Jun 4, 2009 at 10:10 AM, Maarten Maathuis <madman2003@gmail.com> wrote:
> xf86-video-nv which i guess you're using doesn't unconditionally
> support dual link dvi. Some bios'es don't init it appearantly.
>
> There is an option to force it, but you could end up with a blank screen.
>
> Option "AllowDualLinkModes"
>
> Maarten.
>

I added Option "AllowDualLinkModes" to my Xorg.Conf, but the options for the higher resolutions aren't showing up. I know it's just the settings though - the resolutions work fine under windows on the same machine. Any ideas what else I need to add?

P.S. I put it in the Monitor Section, was that appropriate?