Setting screen resolution - xorg

[whitecosmos]

Hey everyone,

I have just installed the F16 XFCE spin and my screen resolution is stuck on 1280x1024, even though my screen is capable of 1920x1080. I have an Nvidia GTX570... I tried editing xorg.conf and xrandr, but I haven't managed to add a new resolution mode to xorg.conf as I don't see the section display in my xorg.conf. As far as I can work out (cat), my xorg.conf only consists of the following:

[root@  X11]# cat xorg.conf
Section "Device"
	Identifier "Videocard0"
	Driver "vesa"
EndSection

Xrandr returns "Failed to get size of gamma for output default". Does this mean my graphics card is unsupported?

Thank you all very much,
whitecosmos

[jpollard]

It is more likely an issue with the monitor attached.

You can look through the /var/log/Xorg.x files and see if your monitor is identified without an error.

Sometimes there is a "EDID checksum error" type message that causes the monitors capabilities to be unknown. This usually results in picking the most generic resolution. Since every video card now in use support 1280x1024, that is what gets used.

[whitecosmos]

Thanks a lot for your answer. My xorg.x logs show the Vendor (BenQ) and even the correct model (G2220HD), still, the modelines in the xorg.0.log and the xorg.9.log (lots of resolutions, including 1920x1080) don't show up anywhere in the settings.

---------- Post added at 06:25 AM ---------- Previous post was at 05:41 AM ----------

I have now changed my xorg.conf to this:

Section "Device"
	Identifier "Videocard0"
	Driver "vesa"
EndSection
Section	"Screen"
        Identifier "Screen0"
        Device "Videocard0"
        SubSection "Display"
                Viewport         0 0
                Depth      	 24
                Modes            "1920x1080" "1280x1024"
        EndSubSection
EndSection

It didn't change anything. Did I make any mistakes or does it just not make sense to tell xorg about a screen Screen0 it doesn't know yet?

Thanks a lot,
whitecosmos

PS: http://xkcd.com/963/

[nsnbm]

Hello whitecosmos,

The way in which I changed the resolution was to bootup without X running and run as root:

Xorg -configure

This leaves an xorg.conf file in root's home directory which you can modify and transfer to /etc/X11/xorg.conf. In that file you can make the mode adjustment which you require by including the new resolution. It looks to me that the vesa driver in your xorg.conf is a fall-back from the open source nouveau driver which is usually used for nvidia cards as I understand it. If you wish to use the nvidia proprietary driver you could hunt up the process to install that in this forum. If the Xorg generated file misses the nouveau driver, you could try changing the driver from "vesa" to "nouveau" . Other than that I don't know what to try. Ben.