The HP ProDesk 400 G1 has a faster storage speed than most PCs of a similar age and spec to it. This HP desktop computer has an SSD storage medium, whereas most personal computers that have been on the market for around the same time as it 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.
An SSD storage medium is actually the best storage speed across all computers of this age and spec.
Across comparable types of desktop computer the worst storage speed is HDD.
It may also be worth considering one of the alternative SSD personal computers currently available including because of it's better review score, the Fujitsu Q520.