Thin is in. It doesn't matter if we're talking laptops, tablets, phones or TVs, these days less is considered more and that even applies to the humble NAS. As such we find ourselves testing the Synology DiskStation DS411slim, an evolution of the excellent (if rather chunky) DS411j.
While not strictly a successor (the DS411j supports 4x 3.5in HDDs, the slim just 4x 2.5in) the design of the DS411slim shows just how important svelte lines have become to all aspects of technology. Gone are the DS411j's white and beige colouring to be replaced by a mixture of matt and gloss black and the jutted front of the DS411j is replaced by a more rectangular and minimalist form factor. The slim also lives up to its name: disk free it measures just 120 X 105 X 142 mm and weighs 660g. All in all the slim is about as attractive a NAS as we can remember, build quality is top notch and drives bays slot in without the need for screws. If this is a glimpse of the styling Synology will use across future lines then it bodes very well indeed.
Equally promising is what Synology has done on the inside. Compared to the heftier DS411j, the slim has received a decent processor bump from 1.2GHz to 1.6GHz while memory has been upgraded from 128MB of DDR2 RAM to 256MB of DDR3. Just a single 60 x 60 x 10mm fan sees the slim produce a barely detectable 21.1dB of noise, though this will change depending on the noise of each drive you add.
Of course here we hit a snag inherent in any 2.5in-only NAS: capacity and cost. For while the DS411Slim is small, light and quiet and can hold four drives, the most capacious 2.5in HDD is just 1TB. This means a maximum internal capacity of 4TB, or 3TB with redundancy. With 4TB 3.5in HDDs now shipping a larger 3.5in compatible NAS with four bays can hit 16TB. 2.5in drives are also far more expensive per gigabyte so you'll be paying more for less. It is worth noting the slim has two USB 2.0 ports and one eSATA for connecting additional external drives, but such extra bulk would ruin the point of buying a sleek NAS in the first place. The key message is to remember Synology is selling the NAS equivalent of an iPad nano, not a Classic.
None of which is to say the slim is under featured. Despite its diminutive size the DS411slim ships with the same DiskStation Manager (DSM) software as Synology's premium lines, including the DS712. For our money DSM is one of the most intuitive NAS user interfaces currently available. It mimics the Mac OS X desktop (a live demo can be tried here) and uses rich graphics and an icon driven windows system (which includes multitasking and drag and drop) to make even complex actions relatively straightforward. This is vital because the functionality of the slim is immense.
It is *deep breath* DLNA and UPnP compliant, has iTunes Server built in, can stream Internet radio stations or even iPod playback (with optional USB speakers) and downloads over BitTorrent, FTP, HTTP, eMule and NZB (Usenet) without needing a PC. Mobile apps for iOS and Android also enable remote control, data access and printing and with a compatible IP camera the slim offers remote surveillance via a web browser.