The HP mt40 has an SSD storage media which is better than the HDD storage media found on most similar spec notebook PCs that have been on the market for a comparable time to it. 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 media is in fact the best storage medium across all medium processor cores portable PCs that have been on the market for a comparable time to the mt40.
The worst storage medium across comparable types of notebook PC is HDD.