The 6TB version of the SanDisk Professional G-Drive ArmorATD ($219.99) boasts the maximum capacity available in a 2.5-inch portable hard drive, and offers some protection against water and being dropped or crushed. As a spinning platter drive, its speed is typical of its class -- which is to say, a slowpoke compared with solid-state drives (SSDs) -- so it's less than ideal for users needing to back up many large files in a hurry. The ArmorATD also lacks software, encryption, and backup features like those provided with the Editors' Choice-award-winning WD My Passport. But it should work well for travelers or mobile workers who crave more storage than speed.
Measuring 1.3 by 3.5 by 5.2 inches and weighing 0.8 pound, the 6TB ArmorATD is hefty for a portable hard drive, a bit larger and heavier than the 2TB version of the drive that I reviewed back in 2021. (The extra bulk is likely dictated by the additional platters that the 4TB and larger versions of the drive require; see the table of available capacities below.) The ArmorATD can fit in one hand -- I found it easy to grip the black, rubberized bumper that cushions the drive -- and you could slip it into a pants pocket, albeit with little room to spare.
The device's gray surface shows through a removable sheath that protects the unit on top and bottom. On the side, a plug attached to the rubber enclosure conceals a USB-C port with a USB 3.1 Gen 1 interface. The port also works with the Thunderbolt ports on all recent Macs. The ArmorATD comes with a pair of 2-foot cables, one USB-C-to-USB-C and the other USB-C-to-USB-A.
As a rule, spinning hard drives are more fragile than SSDs, which have no moving parts. That said, the ArmorATD -- the acronym stands for "all-terrain drive" -- has at least some degree of ruggedness, while most external hard drives offer little or none. With a rubber bumper cushioning its aluminum frame and internal shock mounts, it's rated to survive up to 1,000 pounds of pressure or a drop from 3.3 feet. Its ingress protection (IP) rating of IP54 provides some security against sand and rain, though it's still potentially vulnerable to fine dust. You can splash water on (but not immerse) the unit with no ill effects. Note that the drive's protection against dust and water is contingent on its USB-C port being covered.
The bottom line is that the ArmorATD is moderately rugged. A hiking trip that involves the need for data backup, say to save photos, should pose no threat, and trips around town should be a breeze. The Silicon Power Armor A66 offers similar drop protection, but its IPX4 ingress protection rating means that although it offers the same water-fastness as the ArmorATD, it's vulnerable to dust and dirt. If you need something more watertight or are heading into particularly dirty or dusty environments, you'll likely have to spring for an SSD. The SanDisk Professional G-Drive SSD sports IP67 water and dust resistance, up to 3-meter drop protection, and 2,000-pound crush resistance. You'll pay more for the G-Drive SSD, but it's much faster and provides useful software in addition to being more rugged.
The ArmorATD has its origin in Western Digital's G-Technology line of Mac-oriented products, which was folded into the SanDisk Professional brand in 2021. (WD bought SanDisk in 2015.) The ArmorATD comes formatted in HFS+, one of two file formats (along with APFS) compatible with the Time Machine backup system in macOS. Unlike exFAT, which is both Mac- and Windows-compatible, HFS+ can be used only on a Mac. If you need to use the ArmorATD with both Windows PCs and Macs, you will need to reformat it to exFAT. This can be done easily enough on a Mac through its Disk Utility, where HFS+ is called Mac OS Extended (Journaled).
If you only have a Windows machine and want to convert the drive to NTFS, you can do so using the Windows Disk Management utility by carefully deleting the HFS+ partition and reformatting the device as NTFS, wiping the drive clean. Third-party utilities such as Paragon NTFS-HFS Converter offer a simple and straightforward way to convert drives between HFS+ and NTFS.
Should you reformat the ArmorATD, you will want to back up all your data first. (The Paragon utility even prompts you to do so.) SanDisk doesn't include any backup or security software with the ArmorATD, while the company's G-Drive SSD supports AES-256 hardware encryption and password protection through its SanDisk Security app.
The SanDisk Professional G-Drive ArmorATD reviewed here, as well as the WD My Passport Works with USB-C and the WD My Passport Ultra, both Editors' Choice products, are part of the first group of 6TB hard drives to have reached the market last May. Previously, maximum capacity had been stuck at 5TB for nearly a decade, and there was speculation that these peripherals -- 2.5-inch spinning hard drives powered from a computer over a USB connection -- had reached their limit. No other company besides WD has released or announced similar products.
In addition to the 6TB version I tested, the G-Drive ArmorATD is available in four other capacities whose list prices are detailed below. The highest capacities (4TB and especially 5TB and 6TB) have the lowest cost per gigabyte, which isn't always the case.
We test external hard drives on our main Windows testbed, equipped with an Asus Prime X299 Deluxe motherboard, an Intel Core i9-10980XE processor, 16GB of RAM, and an Nvidia GeForce RTX discrete graphics card. For our Mac testing, we connect the drive to a Thunderbolt/USB Type-C port on our Apple MacBook Pro test unit.
With the ArmorATD, after formatting the drive to exFAT, we first ran our two Mac-based tests -- the Blackmagic Disk Speed Test and our folder transfer test -- from the MacBook Pro using the laptop's Thunderbolt port. Then, we reformatted the drive to NTFS and ran the Crystal DiskMark, PCMark 10 Data Drive, and 3DMark Storage tests on our Windows testbed PC.
Crystal DiskMark measures a drive's throughput in its sequential read and write speeds. We consider PCMark 10, which measures a drive's ability to perform a range of everyday storage tasks, our most important test for external drives. Although we run the gaming 3DMark Storage benchmark on general-purpose hard drives, the results are moot: You wouldn't want to run games from an external spinning hard drive if you could help it, though high-capacity platter-based drives are good for backing up a game library.
The ArmorATD showed solid performance in all our benchmarks. In PCMark 10, the ArmorATD and the two 6TB WD hard drives we've reviewed led the pack; its score was 9% better than that of its 2TB sibling. And it does get bragging rights (if not fragging rights) as the high scorer among these portable hard drives in 3DMark Storage. Its scores in the other tests were in the middle of the pack.
As a portable 2.5-inch spinning hard drive, the SanDisk Professional G-Drive ArmorATD provides massive capacity and is a good value proposition with a low cost per gigabyte. A rubberized sheath and port cover shields it, providing more protection against the elements and accidental drops than most external hard drives offer.
Meanwhile, the 6TB WD My Passport Works with USB-C and WD My Passport Ultra, both Editors' Choice products, are not ruggedized but include the backup and encryption software the ArmorATD lacks. For greater ruggedization cred, you may have to go with an SSD. But if low price, high capacity, and some protection against rain, sand, and tumbles are key, the SanDisk Professional G-Drive ArmorATD may be the way to go.