How to detect and configure an output with xrandr?

I also encountered this problem (used to have a Dell 23" screen)

First, determine which interface is connected to your display:

$ xrandr -q

The command output will be:

mukolla@pk:~$ xrandr -q

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192

LVDS connected (normal left inverted right x axis y axis)
   1366x768       60.0 +
   1280x720       59.9  
   1152x768       59.8  
   1024x768       59.9  
   800x600        59.9  
   848x480        59.7  
   720x480        59.7  
   640x480        59.4  

HDMI-0 disconnected (normal left inverted right x axis y axis)

VGA-0 connected ......

   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  

External display is connected to the port VGA-0. This is important to notice.

Now add a new mode to display:

$ xrandr --newmode "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync
$ xrandr --addmode VGA-0 1920x1080_60.00
$ xrandr --output VGA-0 --mode 1920x1080_60.00

I think you will have gotten somewhere when you get this to increase:

Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200    
                                                  ⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑
 

Then, I think, you will be able to get xrandr to use the custom mode you've learned how to define (if you still need it after fixing the basic problem).

Increase Virtual Screen Size

[This][1] article suggests adding a Virtual line to the Screen section of a xorg.conf configuration file to set the maximum screen size. It's from a couple of years ago. When testing this I wasn't able to set the Virtual line past the maximum screen size given by xrandr -q, however. With my driver and hardware that value was an already quite large 8192x8192, however.

You could experiment by adding this as /etc/X11/xorg.conf, for example:

Section "Screen"
    Identifier "My Screen"
    Subsection "Display"
        Virtual 2048 2048
    EndSubSection
EndSection

You will probably not see a /etc/X11/xorg.conf as today's video drivers will attempt to determine reasonable defaults for everything and modern distributions leave that file out. It will be used if present, however.

If you do already have an /etc/X11/xorg.conf file you can try adding the above Virtual line to the Display subsection of its Screen section

I suggest you test this with a command line editor since there's some chance it will mess up your ability to sign on with the Ubuntu GUI and you may need to do Alt-Ctrl-F1, sign on, and edit (or remove) the file using command line tools. Any errors should in /var/log/Xorg.0.log or /var/log/Xorg.1.log.

In fact, you could and should test this by logging into an additional userid on your system (without logging out of your usual userid) and checking from the new session, that way you can use Alt-Ctrl-F7 to go back to your working GUI if there's trouble. In the case that you are using an additional user id to log in without logging out of the first the appropriate log will be /var/log/Xorg.1.log. Don't log out of the working session or boot until you have a working xorg.conf or have again removed it.

Use a Different Graphics Driver

Another article I read resolved this problem by switching drivers, but I see from your question that the Additional Drivers program doesn't give you any alternatives. (I assume that's what you mean above when you mention the "Hardware Drivers dialog". Unless you change drivers with the Additional Drivers program you will use a driver the kernel deems appropriate for your video card or the video logic on your motherboard.

For the OP, from what you described in your comments above it appears that your system should be using the radeon driver, but isn't. I use the radeon driver and commonly set my horizontal resolution to 1920 (max for the driver/card seems to be 8192). The vesa and fb drivers are very basic drivers for old hardware--old enough that monitors of that era didn't have very large displays.

Upgrade Ubuntu

If you are running a computer newer than the Ubuntu version you have installed and, in particular, its Linux kernel it's completely possible that the kernel won't recognize your graphics adapter. If that's the case you need to upgrade your Ubuntu software which contains support for your equipment.

Since he can't get fglrx to run, this unfortunately is the case for ysap. Because of the newness of this equipment relative to the release ysap is running, there is no support for [1002.9802] in the Lucid (or Maverick either) Linux kernel. First support for this equipment appeared in the Natty 2.6.38 kernel. To check for support for a particular device in kernel modules you can go to /lib/modules/kernel-version/module.alias file and search for the adapter's value. For that equipment:

grep v00001002d00009802 /lib/modules/2.6.38-10-generic/modules.alias

To check Natty's kernel support. It replies:

alias pci:v00001002d00009802sv*sd*bc*sc*i* radeon

As a test, you can try to boot a live CD on the system and try to set the resolution you desire in that environment (click on Try Ubuntu, rather than Install).

Getting appropriate driver support can also enable modern graphics facilities like direct rendering and OpenGL support, greatly improving performance and aesthetics.

For a personal computer you may also be able to use an upgraded kernel if a compatible one is available for your version of Ubuntu. For a production computer it may be necessary to upgrade Ubuntu to a newer version, when available, for the sake of reliability and robustness.

G'day all. I had this problem when connecting to an Ubuntu system which has no screen (used to have a Dell 24" screen, but it was needed elsewhere). I'm not bright enough to know why this works, but here is a series of command which works for me - no file editing required.

Note: that when you reboot, you need to run them again. I suggest a shell script.

gtf 1920 1200 60 -x
xrandr --newmode "1920x1200_60.00"  193.16  1920 2048 2256 2592  1200 1201 1204 1242  -HSync +Vsync
xrandr --addmode VGA1 1920x1200_60.00
xrandr --output VGA1 --mode 1920x1200_60.00

I added the above lines (got slightly different output from the gtf command) to the .xprofile file in my home directory. Worked like a dream. See below.

gtf 1920 1080 60 -x

xrandr --newmode "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync

xrandr --addmode Virtual1 1920x1080_60.00

xrandr --output Virtual1 --mode 1920x1080_60.00

I'm using the Vmware Player, hence the name of the output.