The Mac Pro Late 2013 has an SSD storage medium which is faster than the HDD storage medium found on most PCs of a similar age and spec to it. 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 personal computer's storage speed (SSD) is actually the best storage speed across all medium processor core computers that were launched more than a year ago.
An HDD storage medium is the worst storage speed amongst comparable types of personal computer.