Silicon Power Bolt B75 480GB review

Sturdy and classy in its design, will this external SSD outperform our expectations?

Silicon Power Bolt B75 480GB

TechRadar Verdict

The Bolt B75 external SSD is an average storage device at best, and can be undercut far too easily by a cheap DIY external SSD, or our favorite, the Adata SD700.


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    USB Type-C connector

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    Three-year warranty


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    Only average performer

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    Short cable

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    Large size

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When it comes to external drives, solid-state or flash has historically carried such a big premium over traditional spinning hard drives that to buy one – especially a high capacity model – was really only a consideration for the wealthier tech addicts out there.

However, the relentless march of technological evolution means that we now have access to even cheaper SSDs from the main players on the market, with prices likely to dive even further later this year (watch out for November’s Black Friday 2019 by the way).

Silicon Power, which sent us the nimble B10 SSD and the rugged A85 HDD recently, has provided a brand new model to evaluate, the B75 – a military-grade shockproof SSD in an aluminum case (which makes it an external SSD).

Four SKUs are available and retail for anywhere between £25 ($32) for the 120GB model to just over £285 ($370) for the 960GB model. The one we’re reviewing is the 480GB model which retails for £135 ($175), and as you may have noticed, this means that the smallest SKU carries the lowest price per GB for some strange reason. Blame it on the laws of supply and demand.

Silicon Power Bolt B75 480GB


This drive has received a number of design awards internationally and the company’s lead designer got his inspiration from the Junkers F.13, the world’s first all-metal transport airplane. The Bolt B75 consists of two parts: the enclosure proper which contains the controller/connector, and the silver (aluminum) chassis.

This means that you can swap out the internal solid-state drive at any time – you just need the appropriate screwdriver, and you’ll find out that the unit mostly consists of empty space. Having this sort of flexibility helps Silicon Power to make the most out of economies of scale as the internal drives can be used elsewhere.

The flipside is that you can’t afford the sort of tight integration as seen in the Samsung T5. The drive is bigger than expected with an L-shaped wraparound luminous LED indicator, and a grooved, shockproof and scratchproof chassis.

It has a USB Type-C connector (Gen 1 only sadly), and the device weighs only 85g with dimensions of 124.4 x 82 x 12.2mm.


Here’s how the Silicon Power Bolt B75 performed in our benchmark tests:

CrystalDiskMark: 421.5MBps (read); 316.9MBps (write)

Atto:  460MBps (read, 256mb);  447MBps (write, 256mb)

HD Tune Pro: 276.5MBps (read); 0.086ms (access time)

AS SSD: 404.8MBps (seq read); 409.25MBps (seq write)

Usage and performance

The B75 is an above-average performer – it was faster than the B10 but showed some weaknesses in write performance both in the CrystalDiskMark and Atto benchmarks.

It still relies on SATA technology which limits its transfer rate to the maximum offered by the host connector. As more manufacturers (both of storage devices and host clients) move to Type-C Gen 2 or Thunderbolt 3, expect performance to pick up.

As with the B10, Silicon Power’s B75 offers two bundled application suites:

  • SP Toolbox has some nifty features like wear-out count, a diagnostic scan, a performance test feature and the ability to securely erase data on selected drives.
  • SP Widget lists backup and restore, data encryption and support for Dropbox amongst its main features.

Silicon Power Bolt B75 480GB

The competition

At just over £135 ($175), the 480GB version of the Silicon Power B75 is expensive.

The Adata SD700 is the cheapest 512GB external SSD on the market at less than £100 ($130). It is IP68 rated which means that it is dustproof and waterproof, plus it’s more capacious and smaller than the B75. It’s a shame that the Adata drive is saddled with an old-fashioned USB port, though.

And those who want an external SSD without having to pay through the nose can opt to purchase an external enclosure and pair it with an internal SSD, which are far cheaper. Such a DIY solution will get you a 480GB external solid-state drive for less than £70 ($90), about half the price of the B75. Sure, it won’t be as elegant – but it will be fast enough for most tasks.

Silicon Power Bolt B75 480GB

Final verdict

So, let’s recap: the B75 has a smart design, can be upgraded, and it’s also worth bearing in mind that it benefits from a three-year warranty. On the other hand, it is expensive, just an okay performer, and it’s not waterproof or splash-proof, plus it’s also rather big.

Depending on what your priorities are, the B75 may or may not be the go-to external storage option for you, especially as you can pull the SSD from the casing and put it elsewhere.

For the next iteration, though, we’d love to see Silicon Power try for something cheaper and far more compact, as the printed circuit board containing the actual storage chips occupies only around a third of the actual SSD. Also, a longer cable would be much appreciated; the current one is only 310mm.

Silicon Power doesn’t have its own fabs – the chips inside the drive were from Hynix – and is therefore reliant on third-parties that are often competitors to get its critical components, something that leaves it at the mercy of rivals in many ways.

Desire Athow
Managing Editor, TechRadar Pro

Désiré has been musing and writing about technology during a career spanning four decades. He dabbled in website builders and web hosting when DHTML and frames were in vogue and started narrating about the impact of technology on society just before the start of the Y2K hysteria at the turn of the last millennium.