The HP 640 has an HDD storage medium which is faster than the SSD storage medium found on most recently released PCs. 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.
If you are looking for a PC with a faster storage speed then you might want to consider the 840 (£4,103.79) (SSD), or the 640 MT (£3,115.21) (SSD) both from HP.