2 disk bays, N/A storage supplied, 1x 10/100/1000Mbit/s Ethernet ports
Zyxel is better known for its range of routers than it is for network storage, but the NSA221 is actually the latest in the company's long line of network attached storage (NAS) devices. We had high hopes for the NSA221, especially as Zyxel's previous models have fallen behind the competition in terms of performance and value.
At just under £130, the NSA221 is surprisingly affordable for a NAS with two drive bays and RAID support. Since it's an enclosure, you'll have to provide your own SATA hard disks. Installation is straightforward. The disk bays are hidden behind an easily removable front panel. The included carriers need to be screwed to the sides of each disk before they can be inserted. Unfortunately, it's not clear from the poorly illustrated manual which way up the carriers should be fitted but it's easy enough to figure out with some common sense.
Configuring the NSA221 is straightforward thanks to the logically organised web management interface. Although it initially looks identical to the management interfaces of previous Zyxel NAS devices, it has been streamlined in places. For example, when creating a shared folder, access permissions to that folder can be set without having to go to a separate screen. Similarly, new user accounts can be organised into groups as they're created without having to use a separate set of controls.
Like many other NAS devices, the NSA221 can be used to share a USB printer and the contents of a USB disk across your network. It can also be used as a UPnP media server and as an iTunes music server. Shared media can be browsed and enjoyed through a web interface, although you may the appropriate browser plug-ins to play them depending on which file formats you use. The interface often felt sluggish though, especially when trying to play large movie files or browse through folders full of hundreds of images. Using Windows Explorer was much smoother and trouble-free.
The download manager lets you download files over BitTorrent or from a website or FTP site without the aid of a computer. Unfortunately, the download interface is only accessible to users with an administrator password which would also give them access to the rest of the management interface.
There's also an upload manager that can automatically upload photos and videos from designated folders to Flickr and YouTube, but the NSA221 can only store one set of account details for each service at a time. If multiple users want to upload files to their own accounts, you'll need to frequently alter the NSA221's settings which would be tedious.
File copying performance isn't unuseably slow, but we were expecting faster speeds in a NAS at this price. We used two identical 250GB Hitachi Deskstar disks. Whether configured as RAID 0 or RAID 1, large files were copied at around 12MB/s and small files were copied at around 7MB/s.
Zyxel's NSA221 isn't an awful NAS - if you want RAID support on a budget, then its low price is certainly tempting. You'll have to put up with sluggish performance and some clumsily implemented extra features. If you don't need RAID, we'd rather have the Synology DS110j which is far faster at copying files. If you do want RAID, the cheaper Netgear Stora is better value.