Crucial X6 4TB Portable SSD review: Decent speed, good price to performance

Crucial's X6 4TB is small and simply designed.

Crucial X6 4TB Portable SSD


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The Crucial X6 4TB Portable SSD is a cost-effective pocket-sized external SSD ideal for on-the-go storage for your Mac, with decent access speeds.

If you're carting around a MacBook Air and need some extra storage capacity, there are many options on the market that you could pick up. Main points of differentiation are speed, size, and sturdiness, and it's generally quite hard to find an external drive that can cover all three well.

The Crucial X6 is a very small external SSD that connects over USB 3.1 type C. The size allows you to easily stow it away in a bag and pull it out whenever it's required.

We've been using the 4TB variant, which Crucial rolled out in March 2021. At the time, it joined the roster alongside a 1TB and 2TB version, and the storage producer in parallel also increased the connection speed to match the larger capacity.

Key specs

  • Options for up to 4TB available.
  • USB-C 3.1 Gen 2 connectivity.
  • Compatible with earlier USB versions.
  • Sequential read speeds of up to 800MB/s claimed.
  • 2.7 inches by 2.5 inches by 0.43 inches.
  • 3-year warranty.

Size and design

The unassuming drive is uninspiring in design, but not everything needs to be forged by Jony Ive. It is a small square plastic enclosure, with a USB-C port on one side and the Crucial logo printed on the top panel.

It's not going to win awards with its appearance, but it's certainly adequate and what some would consider a fairly typical appearance for such an item.

The compact size of the Crucial X6 makes it highly portable.
The compact size of the Crucial X6 makes it highly portable.

The drive measures 69mm by 64mm (2.7 inches by 2.5 inches) and is just 11mm (0.43 inches) thick. It's also lightweight at about 40 grams (1.4 ounces).

Crucial has included a short USB Type-C to USB Type-C cable in the box, but if you carry one around anyway, it's one less thing to put into the bag. With a suitable cable or adapter, it can also connect to USB-A 3.0 or USB 2.0 ports at a corresponding drop in speed.

The Crucial X6 is also very thin (Sharpie for scale)
The Crucial X6 is also very thin (Sharpie for scale)

The company notes that the drive has shock and vibration resistance, and it is rated for drops of up to 6.5 feet.

It won't weigh down your bag, and it will easily be able to withstand being jostled around in the bag, too.

Capacity and performance

Before releasing the 4TB version, Crucial's X6 lineup was marketed as having sequential read speeds of up to 540MB/s. The 4TB model alone is rated at up to 800MB/s, all carried over a USB 3.1 Gen 2 Type-C connection, with a maximum bandwidth of 10Gbps.

AppleInsider's testing of the drive using BlackMagicDesign's Disk Speed test put the 4TB model as having read speeds of 677MB/s, while write speeds were 756MB/s. While neither are quite at the 800Mb/s, it is in the ballpark. Both speed tests are still far faster than the sub-4TB models by a long way.

AppleInsider's speed test showed the Crucial X6 4TB is quite quick, but can thermally throttle.
AppleInsider's speed test showed the Crucial X6 4TB is quite quick, but can thermally throttle.

Over 50 sustained tests, we noticed that there was a drop in performance of around 15%. This is either a heat or cache "issue," but is acceptable for everyday use.

Compatibility and support

Unlike some other drives that include security features like onboard encryption, you're looking at a decidedly simpler device overall here. This isn't a high-security drive and is instead a block of storage you can plug in and access whenever and wherever you want.

That said, there's nothing stopping you from using various software-based tools for encryption and backup purposes. Crucial includes support for Apple's Time Machine, FileVault, BitLocker, and Windows Backup.

Naturally, it works with Macs and iPadOS devices, along with Windows, Android, and major game consoles.

In terms of support, you have a three-year warranty from the time of purchase.

Compact and capable

The Crucial X6 4TB Portable SSD is a great answer to the problem of needing extra external storage for your MacBook Pro or iPad Pro while on the move. Its small size, which is improved by reusing USB Type-C cables you may already own for other devices, makes it very easily carried around alongside your hardware.

If you're looking for something that is fully featured, offers enhanced security, and other extras, there are other drives on the market, and this wasn't ever intended to be your solution.

The included cable is short but usable, and doesn't add too much weight or size to the Crucial X6 package.
The included cable is short but usable, and doesn't add too much weight or size to the Crucial X6 package.

Those who want blistering speed at all times may also want to look elsewhere, as some Thunderbolt drives or external RAID enclosures can offer far faster speeds. That said, the speeds observed with the 4TB model are still more than enough for many potential users.

There are cheaper do-it-yourself solutions. You can save a couple of bucks at full retail to shell out around $360 for a 4TB SATA SSD and maybe another $25 for an external enclosure that connects over USB-C, for a total investment of just a bit less than $400. But, you're, you're going to be limited to the SATA bus speed of the DIY model at less than 550Mb/s, a few hundred below Crucial's drive, as well as lacking any of the protective elements.

The Crucial X6 4TB SSD is a no-frills drive, and it gets the job done. It does it without style, and at a good price to performance ratio.


  • Compact and light.
  • Fast connectivity over USB Type-C.
  • Reasonably priced.
  • Drop and knock protection.


  • Uninspiring design.
  • Heat throttles connectivity.
  • No extra encryption features.

Rating: 4 out of 5

Where to buy

The Crucial X6 4TB is available to buy at Amazon for $489.95. It can also be bought from B&H Photo for $489.95.

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