I use VB on several different macs of various vintages and it runs Ubuntu and Win10 guests just fine. Be sure to install the Guest Additions in the guest OS, th

I use VB on several different macs of various vintages and it runs Ubuntu and Win10 guests just fine. Be sure to install the Guest Additions in the guest OS, they provide a bunch of vital drivers - like video, which sounds like what might have been bogging you down.