My external monitor can be activated know (this was an other bug, that I think is related to toshiba_acpi). So I can focus on dual head mode (clone mode is OK).
I tried $ xrandr --output VGA --left-of LVDS xrandr: screen cannot be larger than 1280x1280 (desired size 2560x1024) So I added "Virtual 2560 1024" to the Screen section, as explained in https://answers.launchpad.net/questions/26807. But after restarting gdm, I get a small display where it is explain that Ubuntu use low resolution (800x600) because of a problem. I have this at the end of the output of dmesg : [ 74.605507] mtrr: no more MTRRs available [ 74.606418] mtrr: no more MTRRs available [ 86.487965] mtrr: no more MTRRs available [ 86.488877] mtrr: no more MTRRs available (4 times, but I tried only once). -- External monitor loss - intel 945 https://bugs.launchpad.net/bugs/193419 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs