The ProBook 640 G1 has a better storage medium than most notebook PCs of this age and spec. This notebook PC has an SSD storage medium, whereas most medium processor core laptops that are a similar age to it have an HDD storage medium. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
An SSD storage medium is in fact the best storage medium across all notebook PCs of a similar spec and age to the ProBook 640 G1.
Across similar types of portable PC the worst storage medium is HDD.
Laptops with a better storage medium that might be worth considering include the DELL XPS 13 ($1,932.38) (SSD).