Gdu is intended primarily for SSD disks where it can fully utilize parallel processing.
However HDDs work as well, but the performance gain is not so huge.
Enable snaps on Kubuntu and install gdu-disk-usage-analyzer
Snaps are applications packaged with all their dependencies to run on all popular Linux distributions from a single build. They update automatically and roll back gracefully.
Snaps are discoverable and installable from the Snap Store, an app store with an audience of millions.