The Chromebox M064U has an SSD storage medium which is faster than the HDD storage medium found on most personal computers of this age and type. 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.
This PC's storage speed (SSD) is in fact the best storage speed across all few processor core computers that are a comparable age to the Chromebox M064U.
Across comparable types of PC the worst storage speed is HDD.