Two's company and three's a crowd. But in NAS circles, the real magic starts when you have four drive bays to play with. That's when the circles of ‘data security' and ‘performance' coincide, by striping data across several disks in RAID 5 for added performance and disk redundancy.
So eight drive bays – as we find on the Synology DS1813+ here – must double even the four-way fun?
4-bays good: 8-bays better
An eight-bay NAS will be overkill for all but the most data-hoarding households. And even many businesses too, given that today's hard-disk technology means you could install eight 4 TB disks for an incredible 32 TB total of unformatted capacity.
You can look at eight drive bays as a way to future-proof your storage needs, even if you don't fill them all right away. Or there's the DS1513+ model that sits immediately below the DS1813+ with the same specification but holding five drive bays, for around £150 less.
Synology DS1813+: Features
The DS1813+ is an impressive synthesis of hardware and software. In its black plastic case the Synology doesn't perhaps give the impression of enterprise-class over-engineered build quality. But the build is nonetheless solid and its well-damped materials serve well to remove the metallic ring and clatter of some NAS boxes.
Two large 115 mm diameter fans run slower and quieter than smaller fast-revving types, and there's no additional fan over the processor and motherboard, just passive heatsinks that are ventilated by the main rear-mounted disk fans. The result is one cool and quiet-running chassis.
The hard disk mounting system has been revised for this model, no longer relying on four screws to hold in each disk, but a long snap-on plastic strip on each side. We prefer screws combined with the rubber grommets used in other recent Synology NAS units. But the new rails click into place simply, feel reasonably robust and do save the fiddling with small screws that some people find so off-putting when first setting up a NAS box.
Locking the disks in place is possible, with a supplied hex-sided plastic key like an Allen key, only proprietary to Synology with its extra spline in one corner. It wouldn't stop a determined disk thief but it helps prevent casual or inadvertent popping out of disks, which could destroy a RAID 5 setup if two drives were pulled out at once, for example.
There's a useful range of some of the latest data ports around the DS1813+ to help connectivity and expansion. For example, two eSATA ports are designed primarily to allow Synology's own bespoke add-on drive boxes – a pair of DX513 five-bay unpowered NAS boxes can allow expansion by up to another 20 TB (10 TB capacity, at £390 empty each).
Two USB 3.0 and four USB 2.0 ports are all neatly sited at the back, giving a cleaner front panel – if less convenient access for popping in a portable disk or thumbdrive, compared to NAS models that include front-facing USB.
Four gigabit ethernet ports are included, configurable for failover redundancy or port aggregation. Synology specifies a high 212 MB/s write and 352 MB/s read performance available when set up thus.
To power the DS1813+, Synology has fitted a dual-core 2.13 GHz Intel Atom, the D2700 version with 1 MB of L2 cache and Hyper Threading.
This 32 nm Saltwell/Cedarview chip is well-suited to high-performance and low consumption NAS applications, lacking only the hardware-accelerated AES encryption that's due to appear in Intel's Silvermont update later this year.
Synology DS1813+: Performance
We set up the Synology DS1813+ with eight 4 TB WD Se hard disks, optimised for NAS use. Using a single gigabit ethernet link, we saw up to 112 MB/s read and 80 MB/s write using QuickBench in OS X.
Sustained data delivery was impressive, keeping a steady 109 MB/s read and write, according to the video professional benchmark Blackmagic Disk Speed Test. The disks are clearly not being held back by the NAS electronics or the software, although you'll need to use multiple LAN connections to see the best this server can deliver.
Power consumption is inevitably higher than slower or smaller units. We measured a peak of 90 W fully loaded, and typical average of 82 W. This fell to 26 W for the NAS system alone after the disks had hibernated. That's not bad but seems strangely high for a system using an Intel Atom with TDP of 10 W.
Synology DS1813+: DSM software
Synology's Disk Station Manager (DSM) software remains the jewel in the company's hardware crown. As standard it can serve to Windows, Macintosh and UNIX or Linux client PCs, and Windows shops are well served with domain-joining, while other enterprise-friendly assets include SNMP for network management, WebDAV and Directory Service.
Off-drive backup is of course possible, and HFS+ volumes are now recognised over USB, although we note that Synology's implementation of rsync within the Backup and Restore module is still broken. Even with all Photo Station and similar packages uninstalled or disabled, a backup of a Synology DS1813+ volume to an external drive will result in thousands of @eaDir metadata files and folders littering your destination drive.
It may sound trivial but this coding error is a major annoying inconvenience which makes us hesitate in using a Synology NAS with direct backups to external storage.
Many other frustrated Synology users have discussed this on forums we note, but since no-one has solved the issue despite invoking arcane command-line hacks, it would seem to be a bug that can only be flattened by Synology's software developers.
The Synology DS1813+ is a smart and sophisticated NAS drive, superbly constructed and with a well-judged selection of ports and connectors. There are expansion possibilities too, if up to 32 TB ever proves claustrophobic. A top-spec Intel Atom processor running Synology's latest versatile DSM 4.3 operation system makes a powerful combination that can deliver data quicker than your gigabit LAN. As an overall package, and despite an annoying rsync bug in the DSM software, the Synology cannot escape our test lab without a recommendation.