I set GRUB_GFXMODE to the maximum resolution of my nvidia card, 1680x1050 in /etc/default/grub, then update-grub and it finally works. Plymouth animation is no more Ugly, thanks.
LGDN -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/728781 Title: ugly plymouth animation during booting with nvidia driver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/728781/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs