https://bugs.freedesktop.org/show_bug.cgi?id=86320

--- Comment #8 from Niels Ole Salscheider niels_ole@salscheider-online.de --- This sounds similar to https://bugs.freedesktop.org/show_bug.cgi?id=90340.

Maybe you could try if the problem also occurs in your BIOS screen? I have found similar reports by windows users and it might really be some hw / cable issue.

Apart from that it seems that most (all?) setups that cause problems have a screen with a 2560x1600 resolution...