Big Sur VM is unusable on Catalina host due to 3Mb graphics card limitation Official statement from technical support: Thank you for contacting Parallels Support. This email is in regards to your graphic card usage in Big Sur Virtual machine. In order to use maximum resources in Big Sur Virtual machine, Host OS should also be Big Sur due to the recent API implementation. We are closing this ticket. Please get back to us if you have any other queries. Thank you for choosing Parallels. Have a great day!