Can't change screen resolution to 1280x1024 on Ubuntu with ATI Radeon Mobility X1600
 

I have an Asus A6J laptop with an external monitor. When I try to change the screen resolution in GNOME, I can choose between these resolutions:

1280x800
1024x768
800x600
640x480

How do I change the resolution to 1280x1024?




This is the first time I've tried Linux, so please be gentle ;)

I had the same problem with my video card. You have to modify your xorg.conf located in /etc/X11/xorg.conf to allow for such a resolution.
An example of what you need to changes is this... Scroll down until you see something similar to this:
And I needed to use the resolution of 1440x900 so I added just that:
All I added was the "1440x900". You have more sections such as 8, 16, 24, 32, but you most likely only use 24 (it is the default). But there is no need to delete them, just leave them there and only modify the Modes line. Modify your xorg.conf and dont forget the ""'s. Save it and restart X (Ctrl + Shift + Backspace). And enjoy your new screen resolution!

Hope this helps you out.
DragonM15

Thx for rapid reply...

The problem went away on its own, I think. I booted my computer without the external monitor connected, and behold, the resolution changed to 1280x800.

Hello,

I need help.I just install linux Ubuntu and i have the same problem.I cant make my operating system work with resolution 1280x1024. I read the topic u wrote before some days but when i try do the same i had an error which said i dont have the permissions to change these file. What is it talking about lol!!

It's a pretty vital system file so it's protected from regular users. If it needs to be edited, you have to get the permissions to do so. The magic word is: sudo.

So you do it like this:
make sure that gedit is installed; and then start a terminal and type

sudo gedit /etc/X11/xorg.conf

It will ask for your password and then it will launch the file in gedit.

I still can't do it...Can u please be more specific? :/

After i made the what i want how i save it again ???

I did it !!!!!!!! Thank you very much!!!!!
But now i have to restart my computer and after the restart all will work ?
Thanks again pal!!

Yes, just restart although, in this case, a simple Ctrl + alt + backspace would do as well.

Btw, if you ever need to edit xorg.conf again, do make sure you don't make any typos (a missing blank space or comma can be enough). If you do, you may be unable to get back into your GUI - that can be solved but it's quite uncomfortable until you know your way about Linux a bit better. So always double-check before you either reboot or do the ctrl+alt+bacspace.

I opened xorg.conf but 1280x1024 was already on the list:

ection "Screen"
Identifier "Default Screen"
Device "Generic Video Card"
Monitor "Generic Monitor"
Defaultdepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1280x800" "1024x768" "800x600" "640x480"

I still can't set my resolution to 1280x1024 though.
Any ideas?

Check the "monitor" section for the VertRefresh and HorizSync values, i.e. the minimum and maximum vertical and horizontal refresh rates. Those are directly related to the kind of resolutions that are available; if the maximum rates are lower than what your monitor can actually support, you simply won't be able to get the higher resolutions. In my case, for a 19inch ACER LCD, the VertRefresh is 31-75 and HorizSync is 31-82. Yours may be different because these values vary from one type of monitor to the next. If you have a manual, check whether those values are specified somewhere - if not, search google (that's where I got mine).

This is all there was in the monitor section:

Section "Monitor"
Identifier "Generic Monitor"
Option "DPMS"
EndSection

Section "Monitor"
Identifier "aticonfig-Monitor[0]"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
EndSection

I googled around and found the right vert. and horiz. sync values (56-75 Hz & 30-83kHz, respectively). Can I insert these values manually? If so, what's the right syntax?

my xorg.conf looks like this when it comes to vert/horiz sync values:
Hope this helps you out a little bit.

DragonM15

Tried it, but it didn't make any difference...

No, of course not, vertical and horizontal refresh rates vary according to monitor brand / type. What works for one person, doesn't necessarily work for the other. For example , my own refresh rates (ACER 19 inch LCD) are 31-82 horizontal and 31-75 vertical...

Here is mine; it may work better considering that your monitor seems to have pretty much the same refresh rates as mine. This is a heavily modified xorg.conf as generated by Suse but it should work on any distro - it does for me. If you haven't installed the ATI driver yet, you need to locate the "Device" section and replace "fglrx" with "vesa" or you'll still end up with a blank screen. Then you can install the ATI driver and let it rewrite your xorg.conf or you can do so yourself. You may also receive some errors concerning the paths to your fonts but that shouldn't have any consequences. Also, most distros use video group 0666 instead of 0660 so you could adjust this before you actually give this file a try - unless you are using Suse, of course.