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Last updated 6 hours ago

Apple's SSD prices are pretty high for what you get, so there's a big market for external drives. If you need a massive external SSD, the Oyen Digital U34 Bolt is price-leading and speedy to boot.

Oyen Digital is not one of those brands on Amazon, with too many adjacent consonants making pronunciation impossible. The company has been around, probably without you knowing about them, since the late FireWire days. They've been providing higher-end storage solutions since 2005 or so.

I've purchased a few of their products in what feels like a past life, while doing a job before I went loud writing about things like this, on the Internet, publicly versus very privately. The label plates are all gone or faded, but they still work fine.

I've still got an enclosure or two of theirs that are about 15 years old kicking about, albeit off service, except for very particular needs that pop up from time to time.

And they're still going strong when those needs arise. Oyen Digital's quiet and cost-effective excellence continues in the U34 Bolt external SSD.

Oyen Digital U34 Bolt review - Design and dimensions

The Oyen Digital U34 Bolt measures 4.5 inches by 2.7 inches and 0.75 inches thick, a bit on the chunky side. Most of this is due to heavy-duty construction and the rubber sleeve designed to protect its contents.

At 8 ounces, it's also not light for a portable drive — but that's fine.

On the outside is a silicone sleeve that protects an internal aluminum core. Inside the main enclosure is a silicone inlay meant to prevent further shocks from drops and knocks.

Without the external sleeve, the main core measures 4.35 inches by 2.56 inches by 0.67 inches.

It's constructed to MIL-Standard 810 specs, so it can handle the occasional drop onto the floor. As with any shock-resistant piece of electronics, we don't recommend bouncing it off surfaces too often, but it still gives a bit of peace of mind that a casual fall won't shatter the drive or otherwise kill your data.

Meanwhile, the aluminum core helps manage drive thermals, allowing storage to run as cool and fast as possible.

At one end, next to an indicator LED, is a USB-C connector for USB4 connectivity. That means it can also work with Thunderbolt 3 hosts at up to 40Gbps, as well as USB 3.2 Gen 2x2 20 gigabits per second speeds on PC and Gen 2x1 10 gigabits per second on Mac, respectively.

But there's no reason not to use USB4/Thunderbolt on a new Mac.

Inside the U34 Bolt's aluminum core is an ASMedia ASM2464PD USB chipset and a Phison PS5018-E18 SSD controller, managing Triple Level Cell (TLC) NAND Flash. The flash is paired with 2GB of RAM cache.

Out of the box, the drive is initially formatted in HFS+ for macOS, which is handy for Mac users who want to quickly use the drive — but we still recommend APFS. However, it can be reformatted to use exFAT if you want to use it with both macOS and Windows desktops.

According to the company, the drive is capable of data transfer speeds of up to 2,800 megabits per second when under optimal conditions. This means utilizing a Thunderbolt or USB4 connection and ensuring that the Mac or PC used is fast enough.

Oyen sells the U34 Bolt in 4TB and 8TB capacities. They provided AppleInsider with the 8TB model for review.

Oyen Digital U34 Bolt review - performance

We're accustomed to the 2,800 megabytes per second claims for performance. It's a pretty standard number and has more to do with PCI-E allocation in Thunderbolt than anything else.

Some drives beat the number, but most fall short.

The Oyen Digital U34 Bolt happily exceeds that number. We routinely hit peak transfer speeds of more than 3,000 megabytes per second read and 2650 megabytes per second on my Mac Studio and M3 MacBook Air that I used for testing.

Half-hour data transfers saw no dramatic drops in speed. This is likely because of the speed of the media and the PCI-E 4 capable NVMe media in an enclosure that just can't hit those speeds.

Strangely, though, USB4 speeds on Windows are different. With write caching on or off USB4, we got about half the Thunderbolt speeds, even though Windows reported a full 40-gigabit USB4 connection.

On an actual Thunderbolt port on Windows, though, we saw about the same results as we got on our Macs.

We don't think this has anything to do with Oyen Digital's engineering choices or design. This feels like Windows shenanigans more than anything else — but we'll keep an eye on it.

The enclosure itself is the heat sink for the drive. After using the drive as a boot volume for an Apple Silicon M2 Mac mini for four consecutive days of runtime moving files and playing two 4K videos simultaneously and constantly, the external case was 25C in a 21C office space.

Strangely, after my last few storage reviews, I got asked about case noise more than once. Not coil whine, which you should not get with a well-engineered enclosure and bridge board, but specifically mechanical noise.

This is a curious request, as I've been clear about the lack of fans, and there is no drive chatter like you get with spinning metal drives.

So, the case is quieter than any environment you'd be working in with it. Why this needs to be said, I'm not entirely sure, but here we are anyway.

Anyways, the drive runs cool and maintains speed over time. What's not to like?

Oyen Digital U34 Bolt review - excellent bang for the buck

The price of the 8TB drive is $1,099 at full retail. This is pricey, but it's still in the ballpark of the rest of the market.

For example, the Oyen Digital E18-8TBICS5 is a single-drive 8TB NVMe M.2 PCIe 4.0 x4 drive, which costs about $850 on its own. This makes the drive enclosure and extra protection cost around $150 extra, commensurate with "build your own" pricing.

OWC's 8TB Express 1M2 drive is a comparative product and retails for $1297. It, too, is an excellent drive from an excellent vendor — but the cost difference is clear.

And, as you'd expect, it works fine with a USB-C iPhone. Slap one of those MagSafe wall-mount stickers on the drive, get a short cable, and you're good to go to shoot ProRes footage for a very long time.

Flash media is a commodity, with all that entails, from a financial and consumer perspective. In the summer of July 2024, we've heard rumblings of production changes, which will bring corresponding price increases on SSDs and so forth, as we don't expect manufacturers to tolerate slicing near non-existent profit margins to keep prices static.

So, if you're looking for big external SSDs, now's the time, I think. The Oyen Digital U34 Bolt is a good choice and an excellent value.

Oyen Digital U34 Bolt review - pros

Oyen Digital U34 Bolt review - cons

Oyen U34 Bolt Thunderbolt 4 SSD review — Score 4.5 out of 5

Where to buy the Oyen U34 Bolt Thunderbolt 4 SSD

Oyen's U34 Bolt Portable SSD is available in two capacities — 4TB and 8TB — with retail prices ringing in at $529 and $1,099, respectively. You can pick up either version at Amazon and B&H Photo, though the retailers are running a sale on the 4TB capacity at press time, making it a more affordable option at $459.