Weirdly your kernel command like turned off hardware graphics support for radeon and nouveau but actually seems to have turned off Intel hardware graphics support. It's likely that removing some or all of these from your kernel command line will fix it:
radeon.modeset=0 nouveau.modeset=0 i915.disable_power_well=0 video.use_native_backlight=1 But also please note that Ubuntu 14.04 reached end of standard support in April 2019: https://wiki.ubuntu.com/Releases If you would like to continue with free support then please update to a newer Ubuntu version and tell us if the problem still occurs. If you would like to continue with Ubuntu 14.04 then there is a paid support option detailed at https://www.ubuntu.com/esm ** Package changed: xorg (Ubuntu) => ubuntu ** Changed in: ubuntu Status: New => Won't Fix -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1888746 Title: graphics performance very poor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1888746/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp