I've recently moved my Parallels VMs from a 12-core 2013 "trash can" Mac Pro to a new 16-core 2019 Mac Pro. The Windows 10 VM has 4 CPUs and 16GB of memory-- the settings are identical on both machines. On the older, 2013 Mac Pro, Windows 10 runs smoothly with a fluid UI. On the zipper new 2019 Mac Pro, the same VM runs with a slow and jerky UI. Even the little "balls in a circle" animation as the OS boots is jerky. It's usable, but annoying. There is no other significant load on the system. Adding more CPU cores and memory didn't help. Any ideas, anywone?