The storage speed of this PC is HDD, which is the most commonly found storage medium on computers of this spec and age. 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.
It may also be worth also looking at one of the alternative HDD desktop computers currently available including the EliteDesk 800 G1 Mini, the ProDesk 600 MINI ($571.76), or the EliteDesk 800 G1 all from HP which is cheaper.
Desktop computers with a faster storage speed that might be worth looking at include the NEC Slot-in PC (SSD).