We need our Windows 10 app and our ubuntu app to both run on the same laptop, and communicate by sharing files (probably using Samba file interface between Windows and Ubuntu). There will be a lot of files with a lot of data, being copied from the app on Windows to the app on Ubuntu. The app on Ubuntu will only by copying a few small files the other way.
Which approach (Win VM on Ubuntu or Ubuntu VM on Windows) has best file copy performance?