CalDigit Tuff Rugged External Drive

A waterproof hard drive?

There are a myriad of options when it comes to portable external storage. But if you value durability just as much as portability, those options quickly dry up. Combining a cheap 2.5-inch hard drive with an AmazonBasics enclosure is often just fine for an external storage solution that sits in your climate controlled office all day, but it's probably not the best choice for field use during your national park photography trip, your scuba diving expedition, or on-site construction management.

For situations like these where the elements become a factor and the chance of an accidental drop skyrockets, it's a good idea to invest in "ruggedized" equipment. Companies like Panasonic and Dell have long offered laptops custom-designed to withstand unusually harsh environments, and accessory makers have followed suit with ruggedized hard drives.

Today we're taking a look at one such ruggedized hard drive, the CalDigit Tuff. Released in 2017, the CalDigit Tuff is a 2.5-inch bus-powered external drive available in both HDD and SSD options. CalDigit loaned us the 2TB HDD model for testing.

The CalDigit Tuff arrives packaged in a plastic travel case called an "Archive Box" that accommodates the drive and both USB cables. While the drive offers its own level of durability, the Archive Box provides an additional level of protection while traveling.

The drive is relatively compact, measuring 5.3 inches deep, 3.5 inches wide, and 0.8 inches thick. It feels solid but at 0.6 pounds won't weigh you down while traveling.

The Tuff includes a single USB-C 3.1 port, with USB-C (22-inch) and USB-C-to-USB-A (20-inch) cables included in the box, and features a sealed aluminum and plastic enclosure wrapped in a shock-absorbing silicon bumper. This design provides protection for drops, dust, and water, with the Tuff able to withstand total submersion at a depth of 1 meter for up to 30 minutes. This is compared to a drive like the LaCie Rugged, which can withstand incidental water contact but is not designed to survive submersion. CalDigit advertises that the Tuff meets both IP57 and MIL-STD-810G standards for environmental and shock protection.

Our drive came with the green bumper, but four other color options are available: blue, orange, gray, and black. Those who want to change their bumper color or need to replace a bumper down the road can buy new ones directly from CalDigit for $15 each.

CalDigit ships the Tuff preformatted for Mac users with a Mac OS Extended volume but those with any operating system can use the drive after appropriately formatting it first.


As mentioned, the CalDigit Tuff utilizes a USB-C 3.1 port, which provides up to 10Gbps in bandwidth. For the hard drive-based models especially, however, this spec is irrelevant as the bandwidth of the device is limited by the 2.5-inch SATA hard drive itself. CalDigit advertises "up to 140MB/s" for the HDD model, so we used CrystalDiskMark and ATTO Disk Benchmark to verify actual performance.

In CrystalDiskMark, sequential performance fell just short of CalDigit's claims, with writes hovering just about 135MB/s and reads not far behind at between 131 and 133MB/s. Although we didn't anticipate a performance difference between the USB-C and C-to-A cables, we tested both to verify and, as you can see in the chart, there was indeed no significant difference.

4KB random performance hit about 0.6MB/s writes and 1.5MB/s reads. Random performance is normal considering the limitations of a mechanical hard drive while the sequential performance in particular is relatively good for a 2.5-inch portable drive.

For a second opinion on sequential performance, we turned to ATTO Disk Benchmark. The ATTO results were in line with our initial tests, with writes maxing out at about 137MB/s and reads at just over 130MB/s


Performance is one thing, but CalDigit advertises (and charges extra for) the enhanced durability of the Tuff. While we weren't able to take the drive into an actual danger zone, we simulated several incidents here in the office to stress the Tuff's protective features.

We performed multiple drop tests from as low as 3 feet and as high as 8 feet onto both our low-pile office carpet and the ceramic tile in our office entryway. The drive bounced, rolled, and skidded but continued to perform perfectly when reconnected to our PC.

For the water test, we filled up a plastic drawer with cold water and simply tossed the drive in (making sure that the silicon cover was secure over the drive's USB-C port). We weren't able to test submersion to the full 1 meter that CalDigit advertises (because we simply didn't have a suitable container that was large enough), but we left the Tuff completely submersed in about 6 inches of water for over an hour.

At the end of the test, we removed the drive, allowed it to dry off completely, and then carefully exposed the USB-C port, making sure to have paper towels on had to spot-dry any remaining water that may have been caught under the bumper. Once we were confident that everything was dry, we connected the drive to our PC and, somewhat amazingly, everything worked fine.

The one issue we encountered is that the drive's serial number, which is printed on an adhesive label stuck to the edge of the drive opposite the USB-C port, fell right off following the water test. This isn't a major problem, especially considering that the protection of the drive's data is the most important factor, but those likely to get this drive wet may want to make a separate note of the serial number in the event that it is required for warranty service.

Once our durability tests were complete, we took a look inside. The drive can be opened by prying off the plastic covers on the ends of the drive to expose four Phillips screws. Removing the screws allows you to pry off the outer covers, including the SATA to USB adapter. These two covers are surrounded by a water proofing gasket. Once those are removed, the drive can be slid out of the aluminum chassis, although this is a bit tricky as the drive, too, has its own inner gasket.

With everything removed, we discovered that the drive powering the Tuff is a Seagate ST2000LM007, a 5400rpm drive with 128MB of cache. The Tuff's construction and reliance on multiple gaskets gives us confidence in the drive's water resistant capabilities, but be aware that disassembling the drive as we have will likely compromise this protection. We had difficulty reinserting the tight-fitting gaskets and we're not confident that the drive once reassembled will offer the same water proofing ability. Therefore, save your own disassembly for a last resort in the event of data loss or mechanical failure.

Pricing & Conclusion

Our time with and testing of the CalDigit Tuff revealed that it offers both good performance and peace of mind. These benefits, however, come at a high cost. The 2TB CalDigit Tuff we tested carries a list price of $179.99, with the 1TB SSD model jumping all the way to $449.99.

Compare this to the 2TB LaCie Rugged USB-C, which comes in at $109.99, or the 2TB WD My Passport at $69. Of course, the LaCie doesn't offer protection from water submersion and the Western Digital drive offers no specialized protection at all.

We can therefore only recommend the CalDigit Tuff for users who expect a high likelihood of environmental hazards. For everyone else, if you value your data, picking up two cheaper external drives and mirroring them for backup purposes may be a better way to ensure data protection. If you truly need the protection from drops, dust, and water, however, you'll get what you pay for with the CalDigit Tuff.

The CalDigit Tuff is available now in the following colors and configurations:

Review Terms and Disclosure
All Information as of the Date of Publication
How product was obtained: The product is on loan from CalDigit for the purpose of this review.
What happens to product after review: The product remains the property of CalDigit but is on extended loan for future testing and product comparisons.
Company involvement: CalDigit had no control over the content of the review and was not consulted prior to publication.
PC Perspective Compensation: Neither PC Perspective nor any of its staff were paid or compensated in any way by CalDigit for this review.
Advertising Disclosure: CalDigit has not purchased advertising at PC Perspective during the past twelve months.
Affiliate links: This article contains affiliate links to online retailers. PC Perspective may receive compensation for purchases through those links.
Consulting Disclosure: CalDigit is a not current client of Shrout Research for products or services related to this review.