There is a bug in KDE's bug tracker that is almost as old as some of our contributors: bug 342056, "Ridiculously slow file copy (multiple small files)", reported by Alexander Nestorov back in 2014. The report is blunt: copying a 15 GB folder of roughly 3 million small files took 5 to 10 hours in KDE, versus about 20 minutes with rsync. One commenter summed up the mood: