For a small business, the consumer-grade NAS boxes such as Buffalo, Netgear, Iomega etc just don't cut it. They are limited in performance, functionality and redundancy facilities. Instead, it is necessary to step up a notch and go with the likes of Synology and QNAP - companies that only make NAS equipment. To that shortlist we would also add the Western Digital DX4000; as the recommended retail price for the DX4000 is £799 that's a bit of a tall order, but by judicious shopping around it is possible to obtain one for the magic figure of £600.
As this level, the build quality is noticeably a notch above the lower priced domestic units. The cases use metal and strong plastics. All these three are solidly made; the QNAP TS-419P II perhaps edges just in front with its metal case and metal caddies for the hard drives.
All three candidates can take four hard drives. These fit into removeable caddies and in each case are 'hot swap', meaning a failed drive can be replaced without stopping the system. All three use standard 3.5" HDDs, but the caddies in the QNAP can also use 2.5" HDDs, or a mixture of the two. So once again, QNAP edges it in terms of flexibility. Once difference between the Synology, QNAP and Western Digital is that the first two come without any drives. This gives more flexibility, but it means that the drives have to be purchased separately, installed and then setup. This is not hugely difficult, but will discourage some people. Both models cost around £400; a 2TB WD Red drive (specially designed for NAS usage) is around £100. Buying a pair brings the cost to about £600, and enables the NAS to operate with 2TB of RAID-1 or 'mirrored' storage. The WD Sentinel is aimed at the buyer who wants a system that is largely ready-to-go. As such, it comes with a pair of 2TB drives already installed. In the model we looked at these were enterprise-grade WD Black drives. So, the Western Digital wins this round.
Low cost NAS units have anaemic processors and small amounts of memory (RAM), but these three boxes are far better equipped. The QNAP has a 2GHz Marvell (ARM) processor and 512MB RAM; the Western Digital has an Intel Atom dual-core 1.8GHz processor and 2GB RAM; the Synology has a dual-core 1.07 GHz ARM processor and 1GB RAM. On the face of it, the Western Digital has the most raw power, but this doesn't mean very much as the quality of the software also determines overall performance. Therefore, this specification is not particularly important.
Redundancy - the ability to cope with a component failure - is a consideration at this level. The Synology has a single power supply and a single network (Ethernet) port; the QNAP also has a single power supply but two network ports - these can be configured in 'failover' mode or aggregate mode for increased performance. The WD Sentinel has dual Ethernet ports and the ability to use two power supplies, albeit only one is provided as standard (a second one costs about £50). So, the Western Digital wins and the Synology is at the bottom of the pile.
The final topic is software. The QNAP uses its own Turbo NAS operating system; underneath the hood this is a customised version of Linux, with what can best described as a web interface with some coverflow features, similar to iTunes. It is comprehensive as well as functional. Synology use DSM (Disk Station Manager); this is also Linux-based and accessed from a browser, but looks and behaves like a desktop operating system (it is sometimes compared to Mac OS X). The WD DX4000 is a bit of an oddity, as it uses Windows Storage Server 2008. This will seem very familiar to anyone use to Windows, and has a friendly front-end grafted on to make the networking facilities more accessible. Both DSM and Turbo NAS have a relatively large number of add-on packages to provide additional functionality (such as anti-virus, cloud computing, customer management software, email etc). Synology has the most, QNAP comes second and WD is a distant third. In terms of software, Synology is head and shoulders above the other two.
So, what is the overall verdict then? Each of these NAS units is well made and provides superb capabilities for any small business, meaning any is a good choice. If they could somehow be merged into one box - Synology's software, QNAP's hardware and Western Digital's packaging and overall attention to detail - it would be awesome. As it is, the customer preferred the Synology, but ended up purchasing a Synology 412+, which has a more powerful 2GHz dual-core processor and twin network interfaces, albeit at an extra £100.