Whenever running a back-up in Back In Time Plasmashell will take a core close to maximum usage. Steps: 1. Add directory to back-up in Back In Time. 2. Press Snapshot->Take snapshot 3. Open top or KSysGuard or top and notice that process plasmashell takes close 100% of a core, more than the rsync of Back In Time.
*** This bug has been marked as a duplicate of bug 378010 ***