Ubuntu – Why does a Ubuntu guest in VirtualBox run very, very slowly


I'm using currently Ubuntu 12.04 LTS as a host machine, and I've virtualized three machines:

  • a Xubuntu 12.04 guest
  • a Windows 7 guest
  • a Ubuntu 12.10 guest

All the guests have the same VirtualBox default settings, but Ubuntu 12.10 is slower!

The installation took 1h 40 min! (Normally, it takes 40 minutes.) Now it is impossible to use it, and all operations are very, very slow.

I'm using VirtualBox version 4.2.4.

Any ideas?

Why is it slow? And how can I make it faster?

Best Answer

I have heard it has something to do with the fact they removed Unity 2D, or somehow the switch to 3D Unity only slows down the VM performance due to the heavy reliance on the CPU handling more that it used to have to. The Linux Outlaws podcast talked about it a bit, but I forget the episode.

Update: The problem is with Virtualbox Guest Additions not providing 3D acceleration in 12.10. See Ubuntu 12.10 unable to use 3D acceleration. Fails to build DRM.