Ubuntu – Enable graphics card in VirtualBox

Some general troubleshooting...

• Make sure Unity can use 3D acceleration - it makes a big difference. Run /usr/lib/nux/unity_support_test -p from the terminal and note whether the last line shows Unity 3D supported: yes. If not, enable it in the VM options.

• Check you have given it enough video memory. The default settings in VirtualBox for guests are pretty low. Give it 64MB at least, and 128MB if you can.

• Check screen resolution. No matter what hardware I try, it just can't seem to power my 4K screen at its native resolution (3840 x 2160). Significantly better experience at 1920 x 1080, scaled.

• Check CPU virtualisation settings. If you have, say, a 4-core CPU don't assign all 4 cores to the VM. If you do that, the VM guest will fight the host for resources and the result is that it will actually run slower. Stick to one or two cores. (There's not much difference between 1 and 2 in my experience, but yours may differ).

• Do the same for RAM as for CPU. Don't assign more RAM than you need - ensure the host has enough left for itself. 4GB for Ubuntu desktop seems fine for practically everything I throw at it.

• I've read that people get better speeds on a mechanical hard disk by using a fixed allocation virtual HDD rather than dynamic. In my experience there's no noticeable difference, but perhaps worth mentioning anyway.

Press RCtrl+F1, then RCtrl+F7. This will reset the graphics adapter (first into text mode (TTY1), then into graphical mode again (TTY7)). I had to do this twice, one time it was just a blank screen with an underscore at the top right, when I hit RCtrl+F7 again, everything showed up like it was supposed to. Thanks so much guys!