The Lenovo Thinkstation P500 has an SSD storage medium which is faster than the HDD storage medium found on most computers of this type and age. 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 actually the best storage speed across all desktop computers of a similar spec and age to the Thinkstation P500.
Across comparable types of desktop computer the worst storage speed is HDD.