The ThinkPad X1 Carbon has an SSD storage medium which is better than most medium processor core notebook PCs that have been available for around the same time as it. Most laptops of a comparable age and spec 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.
This portable PC's storage medium (SSD) is actually the best storage medium across all laptops of this type and age.
Across similar types of portable PC the worst storage medium is HDD.
If the storage medium of this notebook PC is not good enough for you then you might also want to consider the Elitebook 820 G2[pl_2886802_price] (SSD), or the EliteBook 820 G2[pl_2897415_price] (SSD) both from HP.