We recently reviewed the Zyxel NSA310S, an affordable single disk NAS that had a surprising amount of features and reasonable performance. It definitely got our attention, and the promise of slightly better performance and a second disk sounds too appealing to pass up. That's the recipe for the NAS device we're looking at today, the Zyxel NSA325 V2.
The advantage of having a NAS with two disks is safety. You can configure it in RAID 1, so that when one disk fails, you don't lose any data. For back-ups it's a nice fail-safe to have.
The Zyxel NSA325 V2 has room for two 2.5-inch or 3.5-inch disks. It's a compact and practical design, with a USB 3.0 port in front and trays for the hard disks. On the back there are two USB 2.0 ports and a gigabit network port. It runs on a 1.6 GHz Marvell processor and 512 MB of RAM, quite a bit more power than in the NSA310S. The performance is better indeed, but the it's also louder than most NAS devices we've tested.
The firmware is similar to that of the NSA310S. It's perhaps not as comprehensive as the software from Synology or QNAP, but Zyxel includes a lot of features. And its average price of £105 is far lower than what you pay for those other brands.