
The weird thing is that such guest install was done on an Intel Windows 10 host and speed problems appear on an AMD Linux host. With a lot, lot of patience, i had tried to uninstall, reboot and re-install AddOns, that took a whole week, near 166 hours, but that did not help, still the same. On such other host with Linux Manajaro (last LTS kernel 5.x) host, the VMSVGA without 3D accel makes the guest to reach desktop, but so slow that it is unusable, more than half an hour to reach desktop, more than ten minutes to show windows menu after click, more than five minutes to show contextual desktop menu, near two hours to open explorer, near one hour and a half to open notepad, near 45 minutes to open cmd console window, typing the four characters of "CD \" took near two full minutes, listing shown was one character every four or five secons, etc. On such other host with Linux Manajaro (last LTS kernel 5.x) host, the VMSVGA with 3D accel makes the guest to not reach desktop, freezes prior to dots moving, BSOD, etc. On the other host with Linux Manajaro (last LTS kernel 5.x) host, the VBoxSVGA (with and without 3D accel) makes the guest to not reach desktop, freezes prior to dots moving, BSOD, etc. On one host with Windows 10 host, the VoxSVGA + 3D works acceptable. More weird things with Windows 10 guest (after clean install), on two different hosts.
