When a huge amount of files get moved to another location, it seems that when I am starting some apps, they get started quickly, BUT: when they open up, their window-content is just a screenshot of the desktop! For instance, when i want to open system-settings, the mainwindows opens up, but you dont see anything of the settings but nothing as a piece of the desktop-wallpaper!
Unfortunately, the Linux kernel does not favour new processes over existing processes for disk IO, so they need more time to initialize when existing disk IO processes are running.