The HP 840 has an SSD storage media which is faster than the HDD storage media found on most comparable spec computers that were launched in the last 12 months. Solid State Drives (SSD) store information in transistors on a circuit board rather than on optical or magnetic media. This has the advantage of being much faster than a traditional HDD drive.
An SSD storage media is in fact the best storage speed across all comparable spec desktop computers that were launched in the last year.
Across similar types of personal computer the worst storage speed is HDD.