Although fast sequential speeds are important for transferring and backing up large blocks of data to your drive, quick random speeds are essential if you must run programs or games directly off the portable SSD. Drive speed: SSDs provide dramatically faster transfer speeds (less waiting for files to copy) than mechanical drives, and we tested both sequential and random speeds.
For example, we note when reviewers mention that their SSDs run hot too much heat during operation can shorten drive life or indicate that the drive is defective. Since SSD manufacturers don’t report durability ratings for external drives (only for internal models), we keep an eye on customer reviews for reliability information. But better endurance is a bonus, especially if you’re using the drive for high-intensity tasks such as 4K video editing.
You’d have to write hundreds of terabytes of data to even begin to wear out most SSDs, though, and few people approach that limit. A portable SSD should also be sturdily built and not feel creaky or hollow. Since portable SSDs lack moving parts, they are less susceptible than mechanical drives to total failure when dropped, jostled, or subjected to changes in temperature or vibration.