I've disabled ACPI by reverting it in Computer Management/Computer/Properties to a Standard PC
Now the cpu% is much better...
top - 11:56:56 up 4 days, 18:50, 3 users, load average: 0.74, 0.77, 0.81
Tasks: 186 total, 1 running, 185 sleeping, 0 stopped, 0 zombie
Cpu(s): 4.2%us...