Tive muitos problemas com minha RIVA TNT no ubuntu karmic, mas parece que agora consegui a resolução de 1024x768.
Vou guardar este texto para a posteridade como disse o autor em sua citação original.
"Re: Force resolution to 1024x768 (on old hardware with new Xorg)
HorizSync 30.0 - 62.0
VertRefresh "1024x768" "800x600"
NOTE: I changed my H. Sync and V. Refresh values for the NEC 3V
HorizSync = 31.0 - 50.0
VertRefresh = 55.0 - 90.0
HINT: I ended up making a copy of xorg.conf in my home folder because I was having some other problems where I had to use the recovery console and repair the xconf which would overwrite my changes. So keeping the copy in my home folder allowed me to just re-copy to /etc/X11/xorg.conf whenever that happened.
2. Found modeline for 1024x768
Used "X/Config/Resolution" (https://wiki.ubuntu.com/X/Config/Res...%20resolutions) to find this command:
$cvt 1024 768
$ xrandr --newmode "1024x768_60.00" 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
xrandr --addmode default 1024x768_60.00
Now, after all this, I was getting the same "xrandr: Configure crtc 0 failed" error that ola was getting. He seemed to resolve the problem but based on the information he posted, I didn't see the solution.
Here is what I did next:
5. Stop the GDM
$ sudo /etc/init.d/gdm stop
I issued this commend from within the GDM so it promptly booted me out to a message about reloading the logging deamon or something like that.
6. Enter the terminal
I found that in here "xrandr" would do nothing. I guess it only works from within the GDM or when the GDM is running.
7. Start the GDM
$ sudo /etc/init.d/gdm start
When the GDM starts back up, it was in 1024x768. Additionally, xrandr and the Display preferences showed 15 or so resolutions, where before I only had a few. Additionally, I found that after rebooting, the resolution remained set.
Just to make sure I had all the steps down, I formatted and re-installed Ubuntu from scratch and I was able to repeat all the steps as listed here.
I hope this might help someone out there... or maybe just me if I run into it again."