In May, Western Digital released the world's first 6TB portable 2.5-inch external hard drives, surmounting the previous 5TB maximum capacity for these USB-powered devices that had stood for nearly a decade. The WD My Passport Ultra ($204.99 for the 6TB model tested here) is the first of its high-capacity ilk we have reviewed, and it has a lot to recommend it. Pleasing to the eye and sturdy to the touch, the Ultra is a tad larger than the previous-generation My Passport hard drives but still can fit in a pocket. It packs a USB-C port plus a USB-C-to-USB-A adapter for those who need it. It also includes file management and backup software with password protection and supports 256-bit AES hardware-based encryption. Add it all up and you get a new PCMag Editors' Choice high-capacity portable hard drive.

Capacity: 6TB Is the New 5TB

In late 2016—which feels like forever in the rapidly iterating tech world—Seagate debuted the first 5TB portable hard drives in its Backup Plus Portable line. Like previous portable hard drives, they have a 2.5-inch form factor and are powered by a computer over the drive's USB connection. Soon, other drive manufacturers introduced their own similar 5TB products. Then, for the better part of a decade, portable hard drive capacity remained stalled at 5TB. There was speculation that capacity for small portable HDDs had reached its limit—that an additional 1TB platter couldn't be squeezed into such a small frame, or that a 6TB model couldn't be adequately powered over USB.

But WD managed to make it work. In addition to the My Passport Ultra reviewed here, WD concurrently released some other 6TB versions of its drives, including the My Passport Ultra for Mac (which is formatted with Apple File System (APFS), My Passport (which has a micro-B port), WD Black P10 Game Drive, and the SanDisk Professional G-Drive ArmorATD. We will be reviewing several of these models in the near future. No other company has released or announced 6TB portable drives as of this writing.

Design: Stylish, Time-Honored, and Sturdy

The 6TB My Passport Ultra inherits the styling of previous models such as the WD My Passport (5TB). The drive's top is a deep blue (formally, Ultra Blue), the only color available for the Ultra at this capacity, affixed to a matte-black base. The enclosure, which measures 0.9 by 3.2 by 4.3 inches and weighs half a pound, combines metal and plastic and feels like a sturdy, well-built product. (The 5TB version measures 0.75 inch thick, so it's possible WD integrated an extra platter in the drive mechanism here to boost the capacity, versus increasing the per-platter areal density.) The biggest surfaces of the drive enclosure have two textures, with a smooth half and a rippled half bisected by a diagonal center line, while a WD logo occupies the upper-right corner of the top.

(Credit: Joseph Maldonado)

On one of the short ends of the case is a USB-C port. The My Passport Ultra includes a foot-long USB-C-to-USB-C cable and a USB-C-to-USB-A adapter. A status light to the left of the port glows when the drive is connected.

In addition to the 6TB version I tested, WD offers four other capacities for the Ultra, with list prices detailed below. Regarding cost per gigabyte, the sweet spot is the 5TB model, but it may be worthwhile to invest a bit more to get the maximum capacity. WD says that it typically does not provide throughput (sequential read and write) speed ratings for the My Passport hard drives, as they are not high-performance drives.

The My Passport Ultra includes Acronis True Image backup software, plus AES-256 hardware encryption and password protection. Assuming it's implemented properly, AES-256 is currently considered essentially unbreakable. To take advantage of the encryption, you simply install and launch the WD Security app that comes on the drive, enter a password, and optionally add a password hint. By default, whenever you connect the drive to a computer or reboot, you'll be prompted for the password before you can access your data.

WD backs the My Passport Ultra with a three-year warranty, which is standard for portable hard drives from major manufacturers.

Testing the My Passport Ultra: Solid Overall Results

We ran our usual Crystal DiskMark, PCMark 10 Data Drive, and 3DMark Storage tests on our Windows testbed PC with the WD drive in its default NTFS format. We then reformatted the Ultra in exFAT and ran two more tests from an Apple MacBook Pro using the laptop's Thunderbolt port.

On the two tests focused on throughput—Crystal DiskMark and Blackmagic—the WD My Passport Ultra was on the poky side relative to the read and write scores among our comparison group, though still within what we consider an acceptable range. The BlackMagic Disk Speed benchmark measures a drive's throughput for reading and writing various video formats.

On both the PCMark 10 Data Drive benchmark, which measures a drive's speed by aggregating its scores on a variety of everyday storage tasks, and 3DMark Storage, which clocks its performance in several gaming-related scenarios, the Ultra did much better. In fact, it turned in the top score on both those benchmarks compared with other portable hard drives. While you wouldn't want to load or run games from the Ultra—external SSDs have far better 3DMark Storage results—it's a great medium on which to archive them. Assuming an average file size of 100GB per AAA game, you could store about 60 of them.

PCMark 10 is the best indicator of general real-world drive performance among our tests. Although the My Passport Ultra's score here pales in comparison even to the SATA external SSDs we've tested, it leads our group of portable hard drives.

Verdict: Maximum Capacity, Go-Anywhere Capability

Platter-based hard drives have persevered in this age of ultra-fast external SSDs due to their ability to store data at a low cost per gigabyte. Of course, an external SSD is always preferable in a portable drive for ruggedness and slimness. But the cheapest high-capacity external SSDs (at 4TB) are around 7 to 8 cents per gigabyte, while the 6TB WD drive costs about half that per gigabyte at list price. And even as external SSD capacity has climbed, with some models now holding as much as 8TB, portable hard drives were long stuck at a 5TB maximum—until WD came out with its recent 6TB models, including the WD My Passport Ultra.

(Credit: Joseph Maldonado)

The My Passport Ultra has a lot going for it. The drive looks attractive and feels sturdy, and it offers USB-C connectivity. Its overall benchmark performance is solid—its throughput scores were on the low side, but it was the highest scorer among our comparison group in both PCMark 10 and 3DMark Storage. Plus, the built-in 256-bit hardware encryption and the software for file management and backups are nice touches that some other portable hard drives lack.

Last, and far from least, the My Passport Ultra can get you the maximum capacity currently available in a portable hard drive. For all this, it earns our Editors' Choice award.