Machine is 64-bit ACPI motherboard with i5 quad-core
and 8 Gb of memory running Windows 10-Pro host.
Monitor is Acer T232HL touchscreen. Video card is AMD Radeon R7 200.
Installed VirtualBox then created guest virtual machine with
2Gb of allocated memory and 200Gb of fixed virtual disk and 128 Mb
of video memory.
Installed Ubuntu Desktop 16.04, then installed Guest Additions.
3D acceleration is checked and confirmed.
Guest machine is still painfully slow, with refresh errors leaving
some menus blank.