I just installed Ubuntu Bionic (18.04.1) (Unity desktop) on both Oracle VB VirtualBox (5.2.18) and VMware Player (v14). I have Guest Additions on both VMs.
On VB, all graphics interactions are super slow. Opening the Dash takes forever (~ 1min) and opening both LibreOffice Write and Calc take several minutes.
The problem seems to be gnome-shell. When I use nmon, I see 1 CPU at 100% system wait state. When I kill a gnome-shell, that goes away -- for a while. I know gnome-shell is very 3-D graphics intenstive; but VMware doesn't seem to have this problem. I'd rather use VB, but I can't under these circumstances.
I have 3D acceration enabled on both, and I've checked /usr/lib/nux/unity_support_test. I'm using 8Gb Ram on both. I assigned 4 "CPUs". My host is a Dell XPS i7.
Has anyone else been able to get Unity on VB to run 'acceptably' like it's a real machine? It feels like something with the graphics emulation, but I can't figure out what? (Xubuntnu runs acceptibly on VB, but not Unity.)