Something kind of unique about UnRaid is the JBOD plus parity array. With this you can keep most disks spun down while only the actively read/written disks need to be spun up. Combine with an SSD cache for your dockers/databases/recent data and UnRaid will put a lot less hours(heat, vibration) on your disks than any raid equivalent system that requires the whole array to be spun up for any disk activity. Performance won’t be as high as comparably sized RAID type arrays, but as bulk network storage for backups, media libraries, etc. it’s still plenty fast enough.