Just installed 11.10 64bit and followed this guide to install the latest drivers for my Radeon HD 4870.

I have a 24" and a 17" side by side. The larger screen is turned on by default, but the smaller one doesn't work unless I mirror them. When I remove mirroring, the small screen is automatically disabled. I enable it, choose a resolution, and when I press apply I get:

required virtual size does not fit available size: requested=(3200, 1200), minimum=(320, 200), maximum=(1920, 1920)

What am I doing wrong?

  • I have similar setup (but with nvidia 6200), and I am getting the same. Nov 6, 2011 at 9:32

1 Answer 1


**First need to install the restricted drivers for access to aticonfig

I had the same problem. Run sudo aticonfig --initial, to re-initialize your configuration files.

Now I'm not sure if restart was necessary here or not.

Now run 'sudo amdcccle' and you'll be able to configure dual display. Go to Display Manager and choose Multi-display desktop with display(s)... in Multi-Display tab for both monitors. **restart after this, Then disable the "mirror monitors" option in the Ubuntu display settings.

  • I'll try that in a bit and let you know. Nov 6, 2011 at 19:46
  • 1
    In addition, it is important that you also have go back to the "Displays" setting, and enable the dual monitor (on top of what you already did in amdcccle". It is working now on 11.10 :) Fantastic
    – Antony
    Dec 26, 2011 at 17:47
  • Helped me on Ubuntu 12.04 LTS with hp envy m6 :) thanks
    – aikeru
    Nov 1, 2013 at 12:45

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .