The HP Z440 has an HDD storage medium which is faster than the Flash storage medium found on most desktop computers that have been available for the last year. A Hard Disk Drive (HDD) is the traditional storage method for computers. A HDD stores the information on magnetic disks. HDD drives are cheap, but they are slower than Flash and SSD bases storage systems.
An HDD storage medium is actually the worst storage speed amongst all comparable spec desktop computers that have been available for around the same time as the Z440.
An SSD storage medium is the best storage speed across similar types of personal computer.