Portable SSDs
External drives, where the cable and the port decide the speed rather than the flash inside.
A portable SSD is an internal drive in an enclosure, and its speed is set by the USB or Thunderbolt generation it connects over. The same drive that reaches full speed on one port is halved on another, which is why the figures here vary more with the connector than with the flash. Check what your machine actually has before paying for a drive that can outrun it.
What an ordinary portable ssd looks like
| Capacity | 1 TB |
| Read speed | 1,050 MB/s |
| Price per terabyte | $150–200 per TB |
Medians, with values beyond 1.5× the interquartile range excluded so one listing cannot move them. A class holding fewer than 8 drives publishes no baseline at all.
How this class is distributed
36 drives in this corpus sit in this class. By capacity:
| Under 500 GB | 3 |
| 1 TB to 2 TB | 15 |
| 2 TB to 4 TB | 12 |
| 4 TB and above | 6 |
The port and the cable decide the speed
A portable SSD is an internal drive behind a USB bridge, and the bridge is almost always the constraint. Successive USB generations roughly double the available bandwidth, and the drive negotiates the slowest link in the chain: the drive, the cable, the port. A capable drive on an older port runs at the older port’s speed, and a good drive with the wrong cable does the same. The cable supplied in the box is the one that was tested with it, which is a better reason to keep it than most people realise.
What is actually inside the enclosure
These are ordinary SSDs in a case, and which SSD it is decides everything about sustained performance. Manufacturers rarely say. The consequence is that two portable drives with identical headline figures can behave very differently on a long transfer — one holding its rate, the other falling to a fraction of it once the cache fills. Where the drive will be used for large media transfers rather than carrying documents, that difference is the one that matters and the listing will not describe it.
Built to be dropped, within reason
The genuine advantage over a portable hard drive is that there is nothing spinning: an SSD tolerates being knocked, moved while working and carried in a bag in a way a mechanical drive does not. Ratings for drop resistance and water ingress are common in this class and worth reading literally — a stated drop height is from a specific surface, and an ingress rating covers the sealed case rather than an open port. They describe survivability, not invulnerability, and neither protects the only copy of anything.
Encryption, and what it protects
A drive that leaves the building is the one most likely to be lost, which makes this the class where encryption earns its place. Hardware encryption built into the drive is transparent and fast; software encryption from the operating system is free and portable between machines. Either is better than none, and neither helps if the password is written on the case. What encryption does not do is protect against the drive failing, which is a separate problem with a separate answer.
The most expensive storage on this site
Price per terabyte is the highest here of any class, and the premium buys the enclosure, the bridge, the ruggedising and the convenience rather than any additional speed. That is a fair trade for something carried daily and a poor one for something that will sit on a desk, where an internal drive or an external enclosure bought separately costs meaningfully less for the same flash. The question worth asking is whether the drive is genuinely going to travel.
Endurance, and the number that is easy to over-worry about
SSDs are rated in terabytes written, and the figure sounds alarming until it is divided by a realistic write rate. A rating of a few hundred terabytes written, against a typical desktop workload of a few tens of gigabytes a day, is measured in decades rather than years. Endurance matters where writes are genuinely heavy — video capture, a busy database, a drive used for constant large transfers — and for most machines the drive is replaced for being small long before it is worn out. The warranty usually expires at whichever comes first, so it is worth reading both numbers together.
Why the capacity you get is smaller than the one you bought
Drive manufacturers count a terabyte as a trillion bytes; operating systems generally count it as 2^40, about ten per cent more. A 1 TB drive therefore shows as roughly 931 GB before a single file is written, and nothing is wrong. Some SSDs also reserve a further slice as spare area for wear levelling, which the controller uses and the operating system never sees. Neither figure appears on a listing, and together they are the most common reason a new drive looks short on arrival.
A drive that travels is a drive that gets lost
The failure modes for this class are not mechanical. A portable SSD is left in a hotel, dropped in a car park, or taken along with the bag it was in, and any of those ends the same way as a failed drive if it held the only copy. The reasonable posture is that a portable drive is a convenient second copy and a poor sole one — useful for moving work between machines and for having something with you, and not a substitute for a copy that stays where it is. Encryption limits the damage of losing it; only another copy limits the damage of needing it.
Almost none of these state a warranty
This class publishes warranty terms less often than any other on the site — a handful of listings out of dozens. For a drive designed to be carried, dropped and lost, that is the specification most worth having and the one least often given. Where a manufacturer does state it, the term is usually generous, which suggests the drives with something to say are saying it. The practical reading is that the warranty on a portable drive has to be looked up on the manufacturer’s own site rather than trusted to the listing.
Reading these figures
Every number above is a median of what manufacturers publish, not a measurement we took. Where a specification is missing from this table it is because too few listings in the class stated it for a median to mean anything — that is a fact about the listings, not about the drives.
Narrow this class by capacity and budget in the ssd finder.