Only RAM. windows in idle mode shouldn't chew any CPU
And when suspended it doesn't chew any RAM either.
Damned sight faster to restore an open VM session that boot windows...wait...coffee... twiddle thumbs....
Personally I'd sooner just swap a disk over or boot into a
Then you are barking mad.
VM allows you to run two systems in parallel concurrently with windows having FULL access to the host file systems.
It allows you painless backup and restore of the virtual machine to as many snapshots as you have disk space for.
It allows superfast booting of the windows WITHOUT shutting down the host.
It allows windows to be suspended in seconds to free up ram and CPU if you need them, and resumed in seconds when you want it back.
The only downsides are that the hardware is NOT fully under windows control and sometimes that means some hardware wont work the way it was intended, and it means that the screen is a bit slower.
The only possible reason I could have for a real live native windows would be to play games on.
Or if I had some obscure hardware that ONLY ran on native windows.
As it happens, I don't have either requirement.