Samsung Portable SSD X5 review: The world’s fastest external hard drive

Even faster than Samsung’s own trusty T5, the X5 SSD is the new king of high-speed portable drives

IT Pro Verdict

The Samsung Portable SSD X5 is a niche product, but it's unbeatable on its own terms. if you’re looking for the fastest external drive in the world, this is it.


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    Incredibly fast; Very portable; Stylish design


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    Won’t work with regular USB ports; Hugely expensive; Not waterproof

If you're looking for super-fast file copies, it's all about Thunderbolt 3 - the latest high-speed interconnect, capable of transferring data at a massive 40Gbits/sec over a regular USB Type C connector. That's around four times faster than a regular USB 3.1 Gen 2 connection (and a similar step up on the original Thunderbolt specification, jointly introduced by Apple and Intel back in 2011).

While not all devices support the connector, it's gradually becoming a regular fixture on multiple different types of devices. The 2018 Apple MacBook Pro features multiple Thunderbolt 3 ports, while monitors like the Samsung C34J79 use it to carry a display signal and simultaneously convey power and data to peripherals. Now, Samsung has added its first Thunderbolt 3 SSD to the mix.

The Portable SSD X5 is about the size of a smartphone, and comes in 500GB, 1TB and 2TB capacities. It uses NVMe SSD technology, which the manufacturer claims will deliver sequential read and write speeds of up to 2,800MB/sec and 2,300MB/sec respectively, making it around four times faster than most current portable SSDs. You'll need a Thunderbolt 3 interface to connect it to, though - and as usual with cutting-edge tech, it's far from cheap.

And when we say the X5 isn't cheap, we mean it. The 500GB model will set you back a steep 360 - considerably more than a regular USB 3 drive. The 1TB model we tested costs 630, and if you need more space than that there's also a 2TB model available for a whopping 1,250.

Samsung Portable SSD X5 review: Design and features

At 119 x 62 x 20mm the SSD X5 is perfectly pocketable. It's relatively light too, weighing just 150g. There's only a single colour scheme on offer, but it's tasteful, with a glossy silver front and a red enclosure around the back. The only connector is a single Thunderbolt 3 port, with an LED that illuminates when the drive's in use, and a cable is thoughtfully provided in the package.

Preloaded on the drive, Samsung also includes its Portable SSD Software. From here you can check for firmware updates and set a password for the drive's built-in 256-bit AES hardware encryption.

What you don't get is a carry case. That's a shame for such a portable drive, especially since the casing lacks any sort of protection from moisture. We'd feel more confident carrying around the IP68-rated ADATA SE730, knowing it's much more likely to survive an accidental spill or an unexpected rainstorm.

Samsung Portable SSD X5 review: Performance and compatibility

The X5 is built for performance, and boy does it shine. Hooked up to a 2017 5K iMac, the drive delivered sequential read and write speeds of 2,352MB/sec and 1,682MB/sec respectively. That's a vast improvement over the 480MB/sec we got from the X5's predecessor, the Samsung T5, and faster even than the iMac's built-in SSD, which managed 1,058MB/sec and 756MB/sec in the same test. We then plugged the drive into a Dell XPS 15 (9570); once again the X5 excelled, with sequential read speeds of 2,057MB/sec and write speeds of 1,531MB/sec.

Even more impressive is the drive's random-access, multithreaded performance: in CrystalDiskMark's 4KiB Q32T1 test, the Portable SSD X5 achieved insane overall read and write rates of 318MB/sec and 280MB/sec. That means it won't get bogged down even when there are dozens of disk operations going on at once, or when copying a folder containing hundreds of small files. For comparison, the USB-based ADATA SE730 and Samsung T5 SSDs drives managed only around 110-180 MB/sec in the same test.

This amazing performance comes with a catch, however: the drive completely lacks any sort of backward compatibility. If you try to plug it into a regular USB port that doesn't support Thunderbolt 3 it simply won't power on. That's because NVMe drives connect directly to the computer's PCIe bus - something which can't be accommodated over a regular USB interface.

If you're shopping for a portable drive to share files with clients, partners or co-workers therefore, the SSD X5 might not be the ideal choice - unless you're sure that everyone involved has a Thunderbolt 3 port.

Samsung Portable SSD X5 review: Verdict

The Samsung X5 is expensive, it won't work with all laptops, and while it's very portable, it's neither waterproof nor particularly rugged. If we had to buy an external SSD today, we'd opt instead for the Samsung T5 or the ADATA SE730 - both of which are much cheaper and much more versatile.

Durability may not seem like a particularly big concern if you're only going to be using it in an office environment, but if you've got hundreds of GB of files on a drive, it's nice to have the added peace of mind of a bit of protection.

In any case, such complaints miss the point of the SSD X5. Yes, it's a niche product, but it delivers world-beating performance, and the sort of person who wants that won't baulk at the price, nor the need for a high-end host system. On its own terms, therefore, it's unbeatable; if you're looking for the fastest external drive in the world, this is it.


The Samsung Portable SSD X5 is a niche product, but it's unbeatable on its own terms. if you’re looking for the fastest external drive in the world, this is it.