So I am using dual monitors and every time I boot up my machine after entering my password to login, both screens show distorted graphics which eventually go away. I am on Ubuntu 12.10 the OS type is 64 bit and my graphics driver is Gallium 0.4 on AMD RV620. Is there any way to prevent the distorted graphics from showing up at all? The distorted graphics seem to go away after about a minute from logging in to my user account.


This continues to be an issue in Ubuntu 13.10. Is this avoidable?

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  • I have the same problem in my laptop. but am not using a dual monitor – Suhaib Nov 11 '12 at 4:28
  • Could you be more specific about the distortion? Is it blurry, the wrong resolution etc...? I have a problem where my second, smaller monitor is duplicated on my larger monitor along with that monitor's view. Is it something like that? – Rostro May 23 '13 at 20:07
  • Have you tried using the proprietary fglrx driver? – grimpitch May 24 '13 at 9:04
  • @toobsco42 are you using any grub boot options such as radeon.agpmode=-1 ? – fossfreedom May 28 '13 at 19:33
  • @fossfreedom I checked my /boot/grub/grub.cfg config file and I don't see any mention of radeon there. – toobsco42 May 29 '13 at 16:42

your monitor doesn`t suport grubs default resolution

using your favourite editor in sudo open /etc/default/grub For example gksu gedit /etc/default/grub

uncomment line GRUB_GFXMODE=640x480 set it to your monitor resolution

GRUB_GFXMODE=800x600 is a sufficient and definitely supported by your display

update grub with new setings sudo update-grub

and vote for the post, as I don't have enough points to vote yet

  • I just tried this, and it didn't resolve my issue. – toobsco42 Jun 3 '13 at 17:29

this worked for my old white iMac (24 inch display):

uncomment line "GRUB_GFXMODE=640x480" and set to 1680x1050

(this should be a comment to Thomas' answer) 17. January 2020

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