Seagate BlackArmor NAS 420 review:

Seagate BlackArmor NAS 420

Like most high-end NAS servers, the BlackArmor supports self-downloading with its Downloader Management feature. This allows you to run three download jobs at a time. In our test, the feature worked well with sites that require authentication. You can also schedule the downloading job to run at a particular time, for example at night, to avoid bandwidth congestion.

Remote access
The BlackArmor also comes with a very convenient way for you to access its data securely over the Internet via Seagate's free Global Access offering. This method of remote access was introduced first with the Maxtor Central Axis NAS server, but the BlackArmor brings it up a notch.

The BlackArmor supports multiple Global Access accounts, one for each user account on the NAS. For example, User1 can create a Global Access account, then log in to the NAS server via its Web interface to associate that Global Access account with the user account on the NAS. Then, User1 can go to the Global Access Web site and access that private folder as well as public folders on the BlackArmor from anywhere in the world. User2, User3, and so on can also, and all can do this simultaneously. Seagate suggests that the BlackArmor supports up to 50 users.

If logged in to the NAS from a remote location, you can transfer files back and forth between the remote computer and the NAS server. Though this vendor-assisted method of remote access is nothing new and can be found in other NAS servers, like the WD My Book World Edition , Seagate's Global Access enables easy copying of an entire folder from the NAS server to the remote computer, which is not available in the My Book. You won't be able to simply drag and drop the folder, however; instead, once you've selected a folder to download, the NAS server will compress that folder into a ZIP file and you'll need to decompress it once it's downloaded. This helps the file download faster and since Windows (and Mac OS X) support ZIP files natively, we didn't see this as a big hassle.

Back up and Dual Gigabit Ethernet
The BlackArmor offers by far the best backup solutions we've seen in an NAS server. The wizard-based backup software supports a long list of backup options, including incremental and differential backups. You can restore by running a restore wizard, by booting using the included CD, or by mounting the backups into a virtual hard drive and copying data using Windows explorer.

The NAS also comes with many options for backing itself up, including NAS to USB and NAS to NAS. The first allows backing up to USB external hard drives and the latter means you can back up one BlackArmor NAS to another. Either of these options can be used without a computer, at any time--manually or automatically.

The server supports external hard drives formatted using both FAT32 and NTFS file systems, allowing you to simply plug any existing USB drive into the NAS and immediately share its files. The NAS can also format external hard drives using the FAT32 file system, regardless of the drive's capacity. This is really useful, especially as Windows allows you to format only a hard drive that's smaller than 32GB using FAT32.

The BlackArmor 420 NAS server comes with two Gigabit Ethernet ports. These ports, in addition to allowing for the linking of multiple units together for NAS-to-NAS backup, can also be used for aggregation. Currently the NAS works well only with the Fail Over Aggregation option, where if one port stops working, the other will kick in immediately to prevent interruption. Going forward, however, Seagate has suggested that it will release a firmware update to allow the two ports to work together, increasing the throughput speed.

We tested the BlackArmor in both RAID 0 and RAID 1 and its performance was just about the average among other NAS servers we've reviewed.

In RAID 0 (which is optimized for performance and maximum amount of storage at the expense of data integrity), the BlackArmor 420's write speed was at 245Mbps, while its read speed was 567.1Mbps. For comparison, the same numbers for the Synology DS410 were 429.4Mbps and 867Mbps for write and read, respectively.

In RAID 1, which guards data against single hard-drive failure by making only half of the total storage available, the NAS' scores were slightly lower, as expected, at 188.8Mbps and 451.9Mbps for write and read, respectively. Again for comparison, the Netgear ReadyNAS Ultra did much better, with 443.7Mbps (write) and 875.2Mbps (read). Note, however, that the Netgear was set up in its proprietary X-RAID2.

Overall, the BlackArmor 420 posted decent data transfer rates, above average in reading and slightly below average in writing on our charts. With this performance it's capable of handling most data-sharing and media-streaming needs. However, since it offers the most amount of storage of any NAS, we wish its performance were on par with that of the Synology DS410 or the ReadyNAS Ultra.

CNET Labs NAS Performance Scores (Via wired Gigabit Ethernet connection)
(Longer bars indicate better performance)
Seagate BlackArmor 420 (RAID 0)
Seagate BlackArmor 420 (RAID 1)
QNAP TS-259 Pro (RAID 0)
QNAP TS-259 Pro (RAID 1)
Synology DiskStation DS710+ (RAID 1)
Patriot Valkyrie Dual-Bay (RAID 0)
Patriot Valkyrie Dual-Bay (RAID 1)

The BlackArmor 420 worked quietly in our test. We ran into a very unusual situation with it, however, when the NAS didn't work well at all with certain routers that had their QoS features turned on. More specifically, we experienced extremely slow read speed with both the D-Link DIR-655 and the D-Link DIR-825 when their QoS features were turned on. It's recommended that you turn off your home router's QoS when you use it with the BlackArmor 420.

Service and support
Seagate backs the BlackArmor 420 NAS server with a decent three-year warranty; much more than the one-year warranties of many other NAS servers. Toll-free phone service is available weekdays, 5 a.m. to 7 p.m. (PT), or you can e-mail technical support via a Web form. Seagate's support site offers installation and troubleshooting assistance, a download library, a knowledge base, and a drive troubleshooter.

What you'll pay

Best storage devices of 2016 See All


Discuss: Seagate BlackArmor NAS 420 (4TB)

Conversation powered by Livefyre