VT-x feature is supported in both Mac Mini Core Solo and Mac Mini Core Duo. Sometimes VT-x could be locked by firmware. To unlock VT-x do the following: 1. Put your Mac Mini into the sleep mode. 2. Wake up your Mac Mini from the sleep mode. VT-x is unlocked now and you are able to run Parallels Workstation in VT-x mode. After cold reboot you should repeat these steps again. To check VT-x mode for running VM please go to menu Parallels Workstation->About Parallels Workstation and check Virtualization mode. It should be Intel VT-x.