Good looks and functionality are nothing without performance in the NAS world and here the DS411slim's bolstered hardware comes to the fore. Over Gigabit Ethernet (now ubiquitous on all modern NAS) the slim managed extremely impressive read and write times of 57.4MB per second and 42.1MB per second when transferring large 4GB files. By comparison the older DS411j hit just 34.5MB/s read and 26.3MB/s write, in line with the 34.4MB/s and 24.6MB/s of the newer budget focused DS211j. Interestingly the slim's transfer rates are not far off those for the DS712 (57.2MB/s read and 43.2MB/s write) without Link Aggregation.
It is a similar story when transferring smaller files. The stop start nature of small files stops any NAS from getting up a head of steam, but at 24.5MB per second read and 21.1MB per second write it again easily bests the DS411j (19.8MB/s and 17.9MB/s), DS211j (19.9MB/s and 18.1MB/s) and plays in the same ballpark as the DS712 (27.1MB/s and 23MB/s). All of which goes to show when transferring large files 2.5in HDDs are not the speed bottleneck many would have you believe (we used 5,200rpm drives) while transferring small files exposes the weakness in all HDD access times no matter how powerful the NAS.
It is worth mentioning these results were attained using Synology's Hybrid RAID. Like Netgear's X-RAID, SHR allows for disks to be dynamically swapped out for larger volumes without powering down the device. When the new drive is inserted the array is rebuilt automatically and all content is available throughout the upgrade process. SHR is highly efficient as well (storage examples are shown above), though if you want to use a more standard option, JBOD, RAID 0, RAID 1, RAID 5, RAID 5 Spare, RAID 6 and RAID 10 are all available.
So ultimately – unless you crave the capacity of 3.5in drives – the only aspect which can bring down the DS411slim is price. Happily Synology has got this right as well. The slim retails for £229 and while a quick search online reveals minimal web discounts this still makes for an eminently affordable and remarkably stylish NAS device. Yes naysayers will point out that 3.5in-compatible NAS cost little more upfront and subsequently save money because of 3.5in drives' cheaper pricing, but that would be to miss the point. In the slim Synology has created a NAS which is every bit the performance and functionality rival of its larger siblings, but with a more living room friendly demeanour.
The Synology DS411slim won't convert those looking for a capacious 3.5in NAS, but it isn't meant to. Instead the slim sheds size and decibels to create a diminutive yet powerful alternative for those happy to compromise storage but not performance. Synology's DiskStation Manager also remains one of the most ingenious and easy to use NAS UIs on the market and extras like mobile apps, security camera and printer support make it a thoroughly comprehensive solution. Tying it all together is a price tag which won't break the bank, just remember to factor in the higher cost of 2.5in drives.