KDE apps actively use shared memory and open many file descriptors.
So you'll need to tweak sysctl values like that:

  sysctl kern.shminfo.shmall=51200 kern.shminfo.shmmni=1024
  sysctl kern.maxfiles=20000

Remember to save those values in /etc/sysctl.conf after successful testing.

Per-process open files limit should be at least 4000 due to the kded4
file monitoring technique.
