The Chromebox has an SSD storage medium which is faster than most few processor core computers that were released around the same time as it. Most latest few processor core computers have an HDD storage medium. 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 desktop computer's storage speed (SSD) is in fact the best storage speed amongst all comparable spec personal computers that are a similar age to the Chromebox.
The worst storage speed amongst comparable types of desktop computer is HDD.