The OptiPlex 9020 has a faster storage speed than most medium processor core computers that have been on the market for a similar time to it. This desktop computer has an SSD storage medium, whereas most medium processor core computers that came out 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 in fact the best storage speed across all medium processor core computers that are a comparable age to the OptiPlex 9020.
Across comparable types of personal computer the worst storage speed is HDD.
If you would prefer a computer with a faster storage speed then you might also want to look at the Zotac ZBOX PI320 (Flash and higher rated), or the Asus CHROMEBIT (£99.97) (Flash and higher rated).