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

Our Rating :
Price when reviewed : £630
inc VAT (for 1TB)

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


  • Incredibly fast
  • Very portable
  • Stylish design


  • 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 high-end systems. 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.

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Samsung Portable SSD X5 review: What you need to know

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.

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Samsung Portable SSD X5 review: Price and competition

When we say the X5 isn’t cheap, we mean it. The 500GB model will set you back a steep £360 – around ten times as much as a regular USB 3 drive. The 1TB model I tested costs £630, and if you need more space than that there’s also a 2TB model available for a whopping £1,250.

There’s very little in the way of direct competition. The closest rivals I could find are two 480GB models from unfamiliar brands, which actually cost slightly more than the Samsung, coming in at £375 and £385 respectively.

You could also put together your own external Thunderbolt 3 drive by buying a bare NVMe enclosure. The NetStor NA611TB3 costs £300, but then you’ll have to add on the cost of an SSD; for a 1TB Samsung drive that’s £325, so the whole thing works out barely any cheaper than the equivalent X5 model.

If you don’t need the very fastest drive around, you could also consider the X5’s predecessor, the Samsung Portable SSD T5, which uses the USB 3.1 Gen 2 interface to deliver a maximum transfer speed of 540MB/sec. Clearly that’s a lot slower than Thunderbolt 3, but it’s more widely supported, and drives are also much cheaper: prices start at £100 for 250GB and range up to £260 for the 1TB model.

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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. I 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.

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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 I got from the T5, and faster even than the iMac’s built-in SSD, which managed 1,058MB/sec and 756MB/sec in the same test. I 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 SSD drive 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 movies and pictures with your friends and family, therefore, the SSD X5 might not be the ideal choice – unless you’re sure that everyone involved has a Thunderbolt 3 port.

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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 I had to buy an external SSD today, I’d opt instead for the Samsung T5 or the ADATA SE730 – both of which are much cheaper and much more versatile.

But 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.

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