Hey, I think I know what causes this. It's the virtual size. It was clearly written in my xorg.conf, so I should have noticed before. But they stated that the issue was for pre-965 so I didn't pay attention. So it seems that it holds for 965 as well.
Here is it: if I do: xrandr --output LVDS --pos 607x1100 then my virtual size becomes 2047 x 2000, and the display becomes nice and smooth. But if i do: xrandr --output LVDS --pos 607x1100 then the virtual size is 2048 x 2000 and suddenly everything becomes very slow on the external monitor (but, as I said, still smooth on the laptop screen). -- xorg very slow when rotated on external monitor https://bugs.launchpad.net/bugs/174650 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
